Site drainage

The plant site should be properly drained in order to prevent the flooding of safety related facilities. Flooding may occur because of  

The drainage arrangements for the site under consideration should be made available for analysis and inspection. Guaranteeing access to the site, personnel actions at the site and the removal of the excess water should be considered a safety related system. The discharge level of the system should be chosen in such a way as to prevent flooding from affecting the functionality of the system. 

---

Ice, snow, and water removal and control or storage, grounds management, site drainage... 

Water pipes, water demineralization, waste-water treatment plant, site drainage, and sewers ... 

Site drainage waters from surface runoff invariably include some oil picked up from small spills and process leaks. These will also be routed through an API separator first, sometimes followed by a dissolved air separator (Fig. 18.8). Oil separated from this drainage water stream will join the slop oil circuit for recycling. During times of desalter operation when water is short, treated site drainage waters may be used for this purpose. Any water in excess of desalter requirements will proceed to an artificially aerated bio-pond for further BOD reduction before discharge [74]. 

Warehouse Roadway Site drainage Security Phone system Fire protection ... 

Possible sources of waste water are scrap storage area and site-drainage sand preparation... 

Atmospheric oxidation of iron pyrites (FeS2) in coal and associated rocks and rapid dissolution of the resultant sulfur oxides and iron sulfates in percolating waters produce very acidic effluents (acid mine drainage) (Berkowitz, 1985). The extent and toxicity of the waste streams depend on coal characteristics, local rainfall patterns, topography, and site drainage features. Leaching of such waste could lead to an unacceptable level of contamination of surface and groundwater. 

Revised standards should be applied in foil to new-build sites and to new partial installations. On existing sites, it may not be practicable to folly upgrade bunding and site drainage. Where this is so operators should develop and agree with the CA risk-based plans for phased upgrading as close to new plant standards as is reasonably practicable. 

Tertiary containment minimises the consequences of a failure in the primary and secondary containment systems by providing an additional barrier preventing the uncontrolled spread of hazardous liquid. Tertiary containment is achieved by means external to and independent of the primary and secondary containment systems, such as site drainage and sumps, diversion tanks, impervious liners and/or flexible booms. Tertiary containment will be utilised when there is an event that causes the loss of containment (for example bund joint failure or firewater overflowing from a bund during a prolonged tank fire), and is intended to ensure that loss of control of hazardous materials does not result from such an event. 

Identify vulnerable surface and groundwaters and pathways to them, eg site drainage systems that need to be protected. 

Particularly in the case of natural events, some scenarios are treated as exclusion criteria for the site itself (e.g. local volcanism and local active fault) and so they are not discussed here [14]. Other scenarios are dealt with preferably through site protection features (e.g. the dry site concept, site drainage, protecting dams and levees) rather than by plant design measures and therefore they are discussed in the relevant publication on site evaluation. 

Information on site drainage and other man-made potential pollutant pathways, e.g. underground services Yes D/No ... 

Figure 13.4 Incident response plan should include site drainage plan...

Specialist clean-up contractors >- Site keyholders >- A site drainage plan showing ... 

---