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underlying layer of dry soil as shown in Fig. 6b. Around 66–67 m, there was a downward progression of different resistivity zones (1000–2500 Xm, then 250–530 Xm, and 530–1100 Xm) which TP6 on AL1 revealed as demolition waste close to the surface, fol- lowed by a gentle progression of semi-wet to dry soil as shown in Fig. 6c. However,Fig. 5b also revealed a structure between 28 and 44 m along the line, with resistivity similar to that of exca- vated demolition waste. In this case, it was clearly not demolition waste but a part of the geological formation of the area, as evi- denced by a similar structure underlying the dump in Fig. 5a. This was further revealed by TP9 at 40–42 m on AL2 (Fig. 5b) as compact and dry soil similar to the one in Fig. 6h. Glass hotspots were expected to be in the dark orange to dark red zones (>8000 Xm). There were a number of such zones on all three lines in Fig. 5.OnAL1 (Fig. 5a), three TPs were excavated between 11 and 15 m (TP1), 23–25 m (TP2) and 43–45 m (TP4) and all revealed glass, although it was more abundant at 23– 25 m and 43–45 m (Fig. 6d). As such, these two regions were identiﬁed as hotspots from which materials for physico- chemical characterisation were sampled as samples S1 and S2 respectively. Although the region between 11 and 15 m was also a glass hotspot, it was not sampled but glass abundance was visu- ally qualiﬁed based on amounts of other waste fractions seen during excavations. On AL2 (Fig. 5b), a TP between 13 and 18 m (TP7) also showed abundant glass waste as shown in Fig. 6e. The region around 4–10 m in Fig. 5b clearly contained abundant glass also as could be seen from the surface, but a veriﬁcation TP could not be excavated since the region was sloppy with unstable ground, and thus unsafe for the excavator. Similarly, there was abundant glass on the surface around 29–34 m in Fig. 5b, and therefore the highly resistive region beneath was designated as a hotspot. Materials for physico-chemical characterisation were thus sampled from the regions between 13 and 18 m and 29– 31 m in Fig. 5b (sample S3). On AL3 (Fig. 5c), TP12 was excavated at 14–16 m which was another glass hotspot and was thus sam- pled as S4. It was noted, however, that the bedrock around the dump showed resistivity similar to some dumped materials. In Fig. 5b, for instance, resistivity >8000 Xm is progressively registered in the region around 0–34 m and between 10 and 15 m depths. A TP excavated at 26–28 m (TP8) and 1–2 m depths revealed big stones (Fig. 6f) with an underlying bigger rock which the excavator could not remove. It was thus concluded that the bedrock was responsible for resistivity zones >8000 Xm other than glass hot- spots. Alsterfors site has granite bedrock with a moraine soil depth of 3–10 m (SGU, 2019). Granite and soda-lime glass have similar Fig. 4.Madesjö glass dump; (a) demolition waste heap at the start of ML1; (b) start of ML2 near the stream; (c) TP excavations across the dump. R.N. Mutafela et al./Waste Management 106 (2020) 213–225 219