Surface-drainage water storage

Diked or curbed areas at tank farm and storage locations will also require provisions for surface drainage and should be divided into suitable drainage areas. These drains should be run to the oily-water sewer main. 

The water storage characteristics of several Minnesota peats in situ, as determined by Boelter (1964), were shown to vary markedly with peat type. Surface horizons of sphagnum moss peat had large pores and released about 80% of the water by volume at low suction (0.1 bar). In contrast, decomposed and herbaceous peats from horizons below 25 cm had small pores, although high porosity, and were not easily drained. They released only 25—35% water by volume under the same suction. These data emphasize that water table fluctuations in a peat profile do not in themselves indicate the quantity of water involved. Furthermore, peat types must be considered in drainage operations. 

Special handling provisions are foreseen for those chemicals classified as dangerous to the environment. Do not allow the substance to enter the drainage system, surface water, ground water, and soil. Therefore, storage must be severely controlled. The release of the substance in the environment is severely banned and reference to local/national rules/laws must be followed. 

The rainwater-collecting surfaces will be the roof of the building and any hard paved surfaces such as patios. Downpipes and drainage pipes then route the water to the storage tank situated, perhaps, under the lawn. An electric pump lifts the water from the storage tank to the point of use, possibly a dedicated outdoor tap. The water is then distributed through a hose-pipe or sprinkler system to the garden in the normal way. 

Salt is also lost in rainwater runoff. Crusting of the surface of the pile by accumulation of insolubles actually helps to limit this loss. The storage pad should be sloped at least 1-2% to remove drainage to a catchment efficiently and to prevent accumulation of surface water [29]. At the same time, the slope should be limited to about 5% [30], above which operation of equipment like front-end loaders can become unstable. On large pads, ditches and pipes can improve drainage. The drainage should be away from any adjacent ground-water system. Otherwise, it can follow the terrain. 

Fig. 10.22 The influence of design factors on corrosion, (a) Storage tanks should be fabricated to allow complete drainage and access to outside surface for painting, (b) The insulation of cool pipe supports may prevent internal or external condensation of an electrolyte film. Insulation may prevent bimetallic corrosion tight insulation may prevent water ingress, (c) Full length, continuous welds are preferred to intermittent, tack ones. Slag and surface oxides must be removed prior to surface coating.

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