Management of Hazardous Waste: 7 Steps | Ecology

This article throws light upon the seven main steps involved in management of Hazardous Waste (HW). The steps are: 1. Identification of Hazardous Waste Gen­eration 2. Data Collection 3. Waste Characterisation 4. Quantification of Hazardous Wastes 5. Identification of Sites for Disposal 6. Conducting EIA 7. Implementing TSDF Programme.

Step # 1. Identification of Hazardous Waste Gen­eration:

Identifying the HW generating indus­tries is the first step. The HWs are classified un­der 18 categories and this information may be used to screen the wastes generated and classifying them as HWs. However, there are few observations that there is a probability of occurrence of wastes in more than one category; and the above classification system does not give any information to understand the toxic charac­teristics of HW.

Few suggestions are also given to improve the classification system. The data available with the State Industrial Development Corporation (IDC), District Industries Centre (DIC), State Pollution Control Boards etc. may be utilised to identify the industries with a po­tential for HW generation.

Step # 2. Data Collection:

After identifying the HW generating sources, the inventory of the data per­taining to HW generation can be developed by conducting surveys through specially prepared questionnaires to each of the identified sources. This should be followed by field visits for data verification.

It is essential that, the data that is obtained from the above option is verified from secondary data (either published data or available for another industry producing similar products). FIW generation rates estimated from plant capac­ity in Indian industries are available in literature. This will help in identifying any misappropriate data and correcting in the database.

Step # 3. Waste Characterisation:

The HW that is gen­erated from the study region should be charac­terised. For this purpose, it is advisable that the samples may be collected from the waste genera­tion source and analysed in the laboratory. Litera­ture data may be used in the absence of primary data.

Step # 4. Quantification of Hazardous Wastes:

The HWs are quantified based on their individual characteristics. The several options of compatibility of wastes with different characteristics should be studied and segregated. The quantity of HWs will be expressed in terms of each category for dis­posal (e.g. Recyclable, Incinerable, or Disposable etc.). The wastes that are recyclable are used/waste oil, lead wastes, zinc wastes.

Step # 5. Identification of Sites for Disposal:

After quantifying the HW, and assessing the probable area requirements for its treatment, storage and disposal, the sites are to be identified. For this pur­pose, toposheets/or remote sensing images of the study region may be used.

The sites are to be physi­cally verified in the field and to draw observations pertaining to the four different types of attributes (viz., Receptor related, Pathway related, Waste characteristics related, and Waste management practices related) available for ranking the sites.

The site with a minimum score out of the available sites for ranking should be chosen as the site for establishing TSDF Physical models are available in literature that give accurate results than the ap­proximate methods available in Guidelines (1991) for ranking the sites for TSDF.

Step # 6. Conducting EIA:

The Environmental Impact Assessment (EIA) should be conducted in the site identified in the above step. The impacts from the project should be identified and public acceptance should be obtained for clearing the site for TSDF. Of the available options for impact prediction, Matrix method gives a better approximation of re­sults as it focuses on cause-condition-effect rela­tionship of the attributes involved in the activity.

Step # 7. Implementing TSDF Programme:

The TSDF programme should be implemented at the final designated site. The site should contain ad­equate provisions for storage, treatment (Stabili­sation, Incineration etc.) and final disposal. Lay­outs for collecting the HW from the waste gen­eration sources should be planned.

The site should have the laboratory facilities to monitor the func­tion of TSDF from time to time. Landfill is the final disposal option in TSDF. The leachate that has percolated should be treated in Effluent Treat­ment Plant (ETP) before disposal. Monitoring of ambient environmental qualities and TSDF per­formance should be done regularly during the post-closure period of landfill (30 years).