Coal mining generates significant adverse environmental impacts. Historically, coal mining has been a very dangerous activity and the list of historical coal mining disasters is a long one. Underground mining hazards include suffocation, gas poisoning, roof collapse and gas explosions.
The term 'OVD' (Optically Variable Device) is used to describe both laser generated hologram images and electron beam generated images. These optically variable devices are created in highly-secure facilities and are at the forefront of overt asset and brand protection programmes.
An Operation and Maintenance (O & M) Manual is a valuable tool in the proper operation and maintenance of a wastewater. treatment facility. Manuals are used during start-up training and provide long-term guidance in standard operating and. maintenance procedures for operating staff.