Contaminated ‘Brownfield’ site in south-eastern Michigan By Zhanyuan Cai And William Chow

Introduction  Location 8 acre site located in south-eastern Michigan in U.S.A.  Site use history farmland and orchards first facility to manufacture and refurbish liquid processing equipment for heavy manufacturing industries various additions were made until now and eventually discontinued.

INVESTIGATION  Primary investigation Dig 10 feet below surface ground  First investigation 1. Drilling 11 soil borings 2. installing 7 monitoring wells near by  Second investigation 1. Drilling 32 additional soil borings 2. installing 24 additional monitoring wells 3. surface sample were also taken

Problems  Volatile Organic Compounds (VOCs) Detected in water saturated soil 10 feet below round surface.  VOCs are harmful chemicals that evaporate easily at room temp contains carbon. 1. Effects from irritation, vomiting, dizziness up to liver damage, kidney damage, central nervous system damage and even cancer. 2. Toxic to both human and animals 3. Harmful to environment  Polychlorinated biphenyls (PCBs) Detected in the soil samples collected from underground.  PCBs are mixture of individual chemicals either oily liquid or solid that are colourless or light yellow. 1. Harmful to human, animals and environment 2. Cause skin irritation- acne, rashes. 3. Cancer

Remediation Methods  PCB – Contaminated Soil 1. In situ vitrification 2. Bioremediation, chemical dechlorination 3. Excavation and offsite thermal destruction 4. In place segregation, excavation and disposal in a landfill

PCB Contaminated Soil Removal  Segregated in place ( before excavation)  Disposed at landfill  Excavation pits were backfilled,compacted  Results  460 tonnes contaminated soil went to landfill.

VOC – Contaminated Groundwater  Groundwater extraction and treatment  In situ bioremediation  Air sparging and soil vapour extraction

Air sparging and soil vapour extraction Contaminated vapour

Conclusions  June 1998( 19 months after system start- up) clean up criteria were met  Project cost was $ 3 million dollar  Brownfield sites can be successfully and efficiently remediate.