Geo-environmental site investigation for Tunceli, Turkey municipal solid waste disposal site

Abstract

The environmental and geological condition of a current solid waste disposal site in the city of Tunceli, Turkey was investigated. Improper geological structure and soil properties of this unsanitary solid waste storage site as well as leachate from this site caused significant pollution in air, soil, and surface water. Natural soil characteristics and geology of the site are presented in this paper. Petrographic properties of vulcanized rubber rocks composed of tuff and volcanic sandstone at the bottom of storage sites and the mineralogical composition of the base composed of these rocks were examined. Permeability of the natural soil and index properties were determined using soil mechanics experiments (moisture content, specific gravity, Atterberg limit tests, sieve analysis, hydrometer analysis, falling-head permeability test, and standard proctor test) conducted on disturbed samples collected from excavated sites and the relationship between mineralogical composition and soil hydraulic behavior was investigated. Natural soil samples of six different parts of the site indicated that, the soil class in four samples is silty sands, sand–silt mixtures, one is clayey sands, sand–clay mixtures and one is clayey silts with slight plasticity. The values obtained using permeability tests for subsoil samples vary from 10−5 to 10−8cm/s. Low permeability (10−7 and 10−8cm/s) at the south part of the site increases to 10−5cm/s at the natural soil of the North side. Extensively faulted and fissured volcanic sandstone levels at the site give potential to waste leachate to reach deep levels. The soil composition, hydraulic conductivity, topographic conditions, and other location criteria in the current solid waste disposal site showed that the current disposal site is not suitable for this purpose.