Chapter XVII - Municipal Solid Waste Landfills

1 325 Chapter 17 Landfills INTRODUCTION Definition The term landfill is used herein to describe a unit operation for final disposal of Municipal Solid Waste on land, designed and constructed with the objective of minimum impact to the environment by incorporating eight essential components described in Section This term encompasses other terms such as secured landfill and engineered Landfills which are also sometimes applied to Municipal Solid Waste (MSW) disposal units.

2 The term landfill can be treated as synonymous to sanitary landfill of Municipal Solid Waste , only if the latter is designed on the principle of Waste containment and is characterised by the presence of a liner and leachate collection system to prevent ground water contamination. The term sanitary landfill has been extensively used in the past to describe MSW disposal units constructed on the basis of dump and cover but with no protection against ground water pollution.

3 Such Landfills do not fall under the term Municipal Solid Waste Landfills as used in this Chapter . Landfilling of Municipal Solid Waste (a) Landfilling will be done for the following types of Waste : (i) Comingled Waste (mixed Waste ) not found suitable for Waste processing; (ii) Pre-processing and post-processing rejects from Waste processing sites; (iii) Non-hazardous Waste not being processed or recycled. (b) Landfilling will usually not be done for the following Waste streams in the Municipal Solid Waste : (i) Biowaste/garden Waste ; (ii) Dry recyclables.

4 326 (c) Landfilling of hazardous Waste stream in the Municipal Waste will be done at a hazardous Waste landfill site; such a site will be identified by the State Government and is likely to be operated by industries of a district/state. If such a landfill is not available, Municipal authorities will dispose the hazardous Waste in a special hazardous Waste cell in the MSW landfill as shown in Fig. Such a cell will be designed as per Ministry of Environment and Forests (MoEF) guidelines for hazardous Waste disposal.

5 (d) Landfilling of construction and demolition Waste will be done in a separate landfill where the Waste can be stored and mined for future use in earthwork or road projects. If such a landfill site is not available, the Waste will be stored in a special cell at a MSW landfill from where it can be mined for future use. Construction and demolition Waste can be used as a daily cover at MSW Landfills ; however only minimum thickness of cover should be provided as indicated in section All excess construction Waste should be stored in the separate landfill cell.

6 (e) All existing and old Landfills will be inspected and boreholes will be drilled for (i) recovery of leachate samples from the base of the landfill , (ii) recovery of subsoil samples beneath the base of the landfill for evaluation of permeability and soil properties and (iii) recovery of Waste samples for Waste characterisation. A minimum of 3 boreholes will be drilled with atleast one borehole for each acre of landfill area. The quality of leachate samples will be compared with (a) the ground water quality in existing borewells 2 km away from the landfill and (b) the Central Pollution Control Board (CPCB) norms for limits of contaminants in leachate.

7 If the leachate quality and the permeability of the subsoil strata is observed to be satisfactory, the existing landfill can continue to operate with bi-annual monitoring of leachate quality in the drilled boreholes. (f) If the leachate quality is observed to be of poor quality with respect to the local ground water quality or with respect to the CPCB norms, steps will be taken to close the existing landfill site and remedial measures adopted. All future landfilling will be undertaken in properly designed and constructed new Landfills .

8 (g) New Landfills will be established as per the norms given in this Chapter for siting (section ), site investigations (section ), design (sections and ), construction and operation (section ) and closure (section ). 327 328 329 (h) The estimated annual cost for setting up and operating new Landfills as per norms given in this Chapter is estimated to lie between Rs.

9 200 to 300 per tonne of Waste generated (at 1998 prices, excluding land acquisition cost). Provisions may be made by the Municipal authorities for allocating adequate financial resources for establishing new Landfills . ENVIRONMENTAL IMPACT AND ITS MINIMISATION The impact of dumping Municipal Solid Waste on land without any containment is shown in Fig. One notes from this figure that such dumps cause the following problems: (a) Groundwater contamination through leachate (b) Surface water contamination through runoff (c) Air contamination due to gases, litter, dust, bad odour (d) Other problems due to rodents, pests, fire, bird menace, slope failure, erosion etc.

10 Landfills minimise the harmful impact of Solid Waste on the environment by the following mechanisms (Fig. ): (a) isolation of Waste through containment; (b) elimination of polluting pathways; (c) controlled collection and treatment of products of physical, chemical and biological changes within a Waste dump both liquids and gases; and (d) environmental monitoring till the Waste becomes stable. landfill design philosophy in the early 1990 s tended towards total containment or isolation of Waste .