28 SEWER DESIGN 



when less than 12 inches in diameter, and all other available profiles, 

 must be submitted with the plans. Upon these profiles must be shown 

 all manholes, flush-tanks, inverted siphons and other appurtenances. 

 The horizontal scale of these profiles must be at least as great as the scale 

 of the corresponding plans, and the vertical scales not less than 10 feet 

 to i inch. Both scales must be clearly shown upon the profiles. Figures 

 showing the sizes and gradients of sewers, the surface elevations and sewer 

 inverts, must be shown upon the profiles with the same frequency, or at 

 the same points, as shown upon the plans. All stream crossings and sewer 

 outlets must be shown upon profiles with elevations of stream-bed, and 

 the normal, high, and low water levels if these data are available. 



4. Detail Plans. (a) Detailed plans of sewer sections and of all 

 ordinary sewer appurtenances, such as manholes, flush-tanks, inspection- 

 chambers, inverted siphons, as well as of any special appurtenance or struc- 

 ture, must accompany general sewer plans. These detail plans must be 

 drawn to such a scale as to show suitably and clearly the nature of the 

 design and all details, such as manhole-frames and covers, iron pipes and 

 valves, flushing-gates, siphons, etc. They should have marked upon them 

 all dimensions, grades and explanatory notes necessary to make them 

 readily intelligible and a complete guide for construction. 



(b) Complete detailed plans for sewage-disposal works must be sub- 

 mitted in all cases where it is proposed to construct works for complete 

 purification at the time of the construction of the sewarage system. If, 

 however, it is proposed to construct only a portion of the complete works, 

 at this time, detailed plans of such portions only need by submitted. In 

 the latter case future provision must always be made for complete puri- 

 fication works, and a reserve area must be shown upon the general plans 

 for these works, and, if possible, a statement of the general type or method 

 which it is proposed to adopt when complete purification works may be 

 required. 



5. Specifications, Estimates of Cost. Specifications for the con- 

 struction of the system of sewers and sewage-disposal works, including 

 estimates of cost of the same, where these have been made, must accompany 

 all plans for original or new systems. With plans for extensions of existing 

 systems, specifications may be omitted, provided these extensions are to 

 be constructed in accordance with specifications filed previously with 

 original plans. 



6. Engineer's Report. A report, which would usually be written 

 by the designing engineer, must be presented with all plans for original 

 systems, giving full information upon which the design is based. This 

 report must include a description of the extent of area which it is proposed 

 to include within the system at the present time and in the future; the 

 estimated present and future population to be served; the estimated per 



