Chapter 23 page 14 . Just above the table mogra posted the othe...

Chapter 23 page 14 . Just above the table mogra posted the othe day .
Acid sulfate soil and rock
Earthworks could expose acid sulfate soil and rock (acid sulfate materials) and this has the potential to impact human health and the environment (risk CT02). The occurrence of acid sulfate materials is dictated by geological conditions and level of oxidation/weathering of the disturbed soil and rock and the degree of disturbance depends on the nature of works.
Spoil proposed for removal has been categorised in accordance with EPA Victoria Publication 655.1 Acid Sulfate Soil and Rock. It is estimated that approximately 2,630,000 m3 of acid sulfate materials could be produced mostly from construction of the tunnels. Because of the geological conditions, acid sulfate materials are not expected to occur in the project’s M80 Ring Road to northern portal element. Similarly, it is expected that works along the Eastern Freeway would encounter only minor quantities of acid sulfate soil and rock. Acid sulfate material volume estimates, broken down by soil and rock, are presented in Table 23-4. The estimates are based on limited sampling and a number of assumptions regarding distribution and so have considerable uncertainty.
Most of this material is categorised as FILL MATERIAL although some meets the definition of Category C Prescribed Industrial Waste, in accordance with IWRG classification. The classification of Category C is based on elevated naturally-occurring fluoride and it is envisaged that EPA Victoria approval could see most of this reclassified as Fill Material (see Section 23.3.1 Contaminated soil).