Fig.2.43. Clearing of sewer water in septics and filtration wells:
a-basic view; b-double-chamber septic: 1-sewerage post; 2-oulet from the building; 3-septic; 4-ventilation post; 5-T-bent; 6-removing pipeline; 7-deepened board; 8-throughput orifice; 9-filtrating loading; 10-filtrating well.
Fig.2.44. Scheme of purifying structures with filtrating trenches:
1-post; 2-well; 3-septic; 4-dosing chamber; 5-separating well; 6-filtrating trench; 7-irrigation network; 8-ventilation post; 9-drenaige network.
Fig.2.45. Scheme of purifying structures of local sewerage with the plots of underground filtration:
1-post of internal sewerage; 2-outlet from the building; 3-septic; 4-separating well; 5-irrigation pipes; 6-ventilation pipes; 7-borded of underground filtration.
Distance between the parallel irrigation pipes in sand- 1.5-2.0m, in sand-loam – 2.5m. Pipes are laid in sand soils with inclination 0.001-0.003, and in sand-loam ones – horizontally. Total length of irrigation piped is determined by dividing the average daily expends of sewer water of the object that is equipped with sewerage by the norm of their load per 1m. Length of irrigators shouldn’t exceed 20m. Size of pipe load depends on soils types, average year temperature of air from 6.1 till 11oC per 1m of absorbing well: for sand – 24l/day, for sand-loam – 12l/day. Cleared in septics sewer water through the dosing device come to separating well and irrigation network.
2.4.9. Arranging of purifying structures
Location (arranging) of purifying structures at plan id determined by the content of structures which are included to the purifying station, and by the relief of site.
Site for the purifying structures is chosen taking into account the planning and buildings of the settlement. Place of purifying structures location is planed lower along the river stream from the city, and it’s obligatory corresponded with the organs of state control. Relief of site should have inclination for providing the self-flowing motion on sewer water through structures.
Site is chosen in beneficial geological and hydro-geological conditions. During this there are taken into account the sanitary-protective zones (gaps), perspectives of city development and wind direction. Width of sanitary-protective zone depends on the method of clearing of sewer water and work capacity of purifying station.
During designing the site with purifying structures it is paid the attention to uniform division of sewer water among the structures, maximal possible joining of separate structures into the blocks, alternate of construction and ability of perspective work capacity growing of station.
Location of structures should ensure the access to them during the maintenance and repair, and also minimal length of communications: trays, channels, pipelines, etc.
Master plan of purifying station is developed in the scale 1:1000 or 1:500. On it are marked main and auxiliary structures and pipelines, and also roads, networks of plumbing and heat-supply, electric-separating devices, cable network of high and low voltage and other.
Master plan takes into account sanitary requirements, fire prevention measures and safety technique.
On the master plan it is obligatory to keep up normative distances between separate structures.
By high-rise location the site of purifying structures should be higher not less than on 0.5m from the maximal horizont of water during flood with taking into account the height of wave dead-flood.
Territory of station should be arranged, planted, lightened and fenced in. Removing of rain water should be provided by vertical planning.