Protective measures excavation

The SPH-2 was proposed at upslope of SPH-1 site i.e near road level above wide terrace covered with debris/slope wash material (Figs. 1 and 6). Two drill holes were drilled at this new site. In hole DH-19 (EL.678.57 m), rock was encountered at a depth of 39 m. In hole DH-15 (EL. 654.51 m) located 100 m downslope of DH-19, sheared rock was intersected at 72 m depth and continued down to 84 m depth, below which rock condition improved. It revealed a fall of rockline by about 57 m between the drill holes DH-15 and DH-19 (penstock area) within a horizontal distance of 100 m. The foundation level of the surface power house may have to be taken down to a depth of 84 m near DH-15. Massive excavation for the foundation along the hill slope and huge slope protection measures were envisaged. Moreover, adequate measures would also be required to prevent ingress of water mainly from river as the foundation of the powerhouse has to go below river level. 

Early in the Corrective Action process, a decision may be made concerning whether or not containment is necessary to protect human health and the environment (HHE). If the release or threatened release presents danger to HHE, immediate action must be taken to halt migration. Under these circumstances, actions termed "Interim Measures" may be required, and excavation or containment measures may be directed by the regulatory agency. However, the Owner/Operator will be responsible for their implementation. In the event that containment is not required as an interim measure, containment may still be needed as part of the overall Corrective Action to halt the pollution migration if wastes or contaminants are to be left on-site. 

In fact, the table did not reflect the economic evaluation of the pressure relief range after the optimization of technology. Because there is not yet accounting the security investment of protective layer, so temporarily ignore it. However, it can be seen from the table, only consider addition of the recovery rate, the reduction of the roadway excavation and maintenance costs, the optimized technical measures added value of 95.037 million yuan than the original program. Thus, the economy of optimized technical solutions is objective. 

New technologies, equipment or control measures available to the industry, such as the use of foams, absorbents, adsorbents, neutralizers, or other means to suppress the level of air contaminates while excavating the site or for spill control, shall be evaluated by employers or their representatives. Such an evaluation shall be done to determine the effectiveness of the new methods, materials, or equipment before implementing their use on a large scale for enhancing empioyee protection. Information and data from manufacturers or suppliers may be used as part of the employer s evaluation effort. Such evaluations shall be made available to OSHA upon request. 

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