Methodology

Unauthorized dumping is happening in both inside as well as outside of the city, while those within city boundaries are generally short lived and act as illegal transfer stations those on the outskirts of the city are generally ‘permanent’.  In this study we attempt to ignore very small dumps that could be due to various causes which force the truck to abandon the load such as break-downs, shortage of fuel, delays, etc.  We attempted to study dumps larger than 8X8m area (20ft X 20ft – a measure easily identifiable by the student volunteers).  The sizes of dumps vary with the location; inside city dumps will be small and waste will be there for around one to two days.  However, in the case of those dumps outside city, dumps are generally larger, more frequented and persist longer.  Generally the organic wastes are degraded rapidly allowing recyclable materials to be picked up rag pickers.  It generally occurs near accessible public and private open land, fallow agricultural land, road sides and at the foot of small hills where land is not owned individually and there is lesser control on the abuse of such common lands.  

The methodology developed here requires a relatively short study duration that included two phases: 1) site observation and visual estimation and 2) data verification and measurement. Whole study area is divided into grids of size 2.7 km × 2.7 km and Google earth (GE) images are used to find waste disposal sites in outskirts of the city.

Fig 1: Location of unauthorized dumping around Bangalore city

1) Site observation and visual estimation
The purpose of site observation is to find the locations of waste disposal sites using GPS and to evaluate the size and composition of the waste based on visual observation (Fig 2). A few student volunteers were trained on site to visually estimate composition of USW as well as to determine the GPS locations of the dumpsite while simultaneously photographing the same.  In order to ensure that there was a good match among the students a mock assessment was carried out at a dumpsite.  These student volunteers rode on motorbikes or scooters in specified grids and determined the locations of illegal dumpsites.  Each pair of student volunteer was allocated 2-4 grids to be completed in 2 days of survey time.  All observations were recorded on hard copy while the hand held GPS also recorded the track and GPS points.  A small camera was used to back up composition estimates by photos.  At the end of the survey all data was downloaded on in a pre determined format and estimates of composition were verified by an expert – corrections if any were made at this time.  A total of 25 pairs of student volunteers carried out the survey for varying number of grids and submitted their reports and made a presentation of their observation to an expert group.  This allowed validation and verification of the data recorded by the volunteers.  The area covered in presented in Figure 1.  Based on visual observation dumps were classified into different categories – plastic waste, organic waste, construction waste, indeterminate waste, old waste and other waste. Average density of different waste categories and waste volume are used to quantify the unauthorized dumps.

2) Data verification and measurement
Around 10% of total collected locations from the first survey were verified by a co-author – a senior student who has carried out many such surveys.  The locations chosen for verification were spread across all the four zones of the city (Figure 1). At each of these locations used for validation the length and breadth were estimated and area determined. The length and breadth of these specific locations were also determined using Google Earth to quantify and minimize errors.  Average deviation was computed between the measured and visual estimated area and between Google earth and visual estimated area.

Table 1: Details about waste categories

Sl. No.	Categories	Details and Description
1	Plastic	Waste with more than 60% of plastic. Organic waste must have degraded with time and ultimately waste has left with plastic. It is generally coming from commercial places.
2	Organic	Waste with more than 60% of fermentable. Waste must be fresh or 15-20 days old, since fermentable get degrade after this duration.
3	Construction	Waste with more than 60% of construction waste. Organic waste must have degraded and finally left with this.
4	Indeterminate	Waste where difficult to see its composition.
5	Other	Waste which is not the part of municipal solid waste. It includes waste generated from specific industries or commercial places.
6	Old	Waste site must be around six months old. Since all organic waste has degraded and plants have started to grow.
7	Recycler rejects	Recycling units where they segregate recycling plastic and eventually left with non recyclable materials and organic waste.