A. 
Pipe and fittings.
(1) 
All sewer mains shall be cement-asbestos with a minimum inside diameter of eight inches.
(2) 
No other specifications for concrete or cement-asbestos sewers are herein contained. The use of other materials is not prohibited and may be done under standard specifications submitted to and approved by the Board of Public Works.
B. 
Manholes.
(1) 
Manholes shall be constructed at every change of line or grade of the sewer main, at every main intersection or branch (except branches for house connections) and in straight runs of main so that the distance between manholes shall not exceed 300 feet; except that, where the grade of the sewer is more than five feet in 100 feet, the distance between the manholes shall not exceed 250 feet.
(2) 
Manholes may be precast of concrete masonry of 1-2-4 concrete, using tight smooth forms or standard cement manhole blocks formed especially for four-foot manholes.
(3) 
Manholes may be built of brick masonry using hard-pressed brick. Every fifth course of brick shall be laid as stretchers, the remainder to be headers. Every brick shall have full mortar joints on the bottom and sides which shall be formed at one operation by placing sufficient mortar on the bed and forcing the brick into it. Horizontal joints shall not exceed 3/8 inch, and vertical joints on the inside of the manholes shall not exceed 1/4 inch. Joints on the inside face are to be carefully rubbed full and struck as the manhole is built. The outside of the manhole shall be smoothly and evenly plastered with cement mortar 1/2 inch thick. Such plaster coat shall be applied in one operation after all brick has been placed and must not be applied by the mason working within the manhole as the brick courses are laid up. Plaster shall be proportioned one part portland cement to 2 1/2 parts mortar sand.
(4) 
Manhole bottoms.
(a) 
Inverts of manholes shall be formed by running the sewer pipe through the manhole, cutting out the top half of the pipe after the manhole has been completed. Concrete bottoms of manholes shall be placed in two layers. The top of the bottom layer shall be level with the horizontal diameter of the pipe, and upon this layer the brick masonry shall be started. The depth of this concrete shall be everywhere at least six inches thick. Particular care must be exercised to ensure this depth under the invert. After the top of the pipe has been cut off and the invert left in the concrete base, a second concrete floor must be applied on top of the original bottom to the height of the top of the sewer pipe leaving the manhole. This floor shall be neatly shaped to meet the cut half of the sewer pipe and shall serve to confine the sewage from overflowing on the manhole bottom if the sewer should flow more than half full.
(b) 
Where the invert of the manhole is below the groundwater level, manholes shall be waterproof on the outside of the plaster coat with suitable bituminous waterproofing to a line one foot higher than the apparent groundwater level. In wet trenches, water shall be kept drained away from manholes until the concrete work is set.
(5) 
No backfilling shall be done until the plaster coat on the outside of the manhole shall have set for 24 hours.
(6) 
In freezing weather, customary precautions of heating materials and after-protection shall be followed.
(7) 
Specifications.
(a) 
Steps. Steps of cast-iron or of galvanized wrought iron, 3/4 inch in diameter, shall be securely placed in the inside of the manhole during construction, not more than 18 inches apart.
(b) 
Diameter. Manholes five feet deep or less shall have an inside diameter of four feet at the bottom. Manholes 10 feet deep shall be five feet in inside diameter, and at intermediate depths the diameter shall be in proportion.
(c) 
Frames and covers. Manhole covers shall be set to the grade given by the inspector. Covers of manholes in streets shall correspond to the type used and approved by the City of Ithaca in 1932, with the frame and the cover to weigh not less than 480 pounds. The depth of the frame shall be eight inches, and the diameter of the cover shall be 24 inches. Manholes in parking areas where no traffic can be expected may use covers of the lightweight type used in the City of Ithaca prior to 1932. The weight of the frame and the cover shall be not less than 245 pounds, and the depth of the frame shall be four inches.
All material found during the progress of the work to have cracks, flaws, blisters or other defects shall be rejected by the inspector. All defective material shall be promptly removed from the site.
A. 
Sewers shall be laid straight to line and grade between manholes.
B. 
The alignment and grade of the sewer line shall be checked from a string line stretched along the center of the pipe between batter boards, at every 25 feet. The batter board grades are taken from the engineer's grade stakes. The elevation of the batter boards above the invert of the pipe shall be constant for adjacent batter boards. Batter boards shall be set at every change in line and grade.
A. 
Handling main material into trench. Proper implements, tools and facilities satisfactory to the inspector shall be provided and used for the safe and convenient prosecution of the work. All pipe and fittings shall be carefully lowered into the trench piece by piece by means of a derrick, ropes or other suitable tools or equipment in such a manner as to prevent damage to sewer main materials. Under no circumstances shall sewer main material be dropped or dumped into the trench.
B. 
Pipelaying. All pipe shall be laid with ends abutting and true to line and grade, so fitted and matched that a smooth uniform invert will be formed. The bottom of the trench shall be shaped so as to conform as nearly as possible to the outside of the pipe, particular care being taken to recess the bottom of the trench in such a manner as to relieve the bell of all load.
C. 
Depth. In streets or highways, sewers shall be laid to a minimum depth of three feet, grade permitting.
D. 
Unsuitable conditions for laying pipe. No pipe shall be laid in water or when, in the opinion of the inspector, trench conditions are unsuitable.
A. 
Joints. Pipe joints shall conform to both the materials and methods of installation of the manufacturer of the particular cement-asbestos pipe furnished for the job.
B. 
Joints in cold weather. No joints shall be poured when pipe is at a temperature below freezing. When the air temperature is below 40° F., the part of the pipe to be joined shall be heated and a paint coat of G-K primer, or equal, shall be applied both to the spigot end and the inside of the bell before pipes are joined preparatory to pouring.
A. 
Cleaning and flushing.
(1) 
The interior of the sewer shall, as the work progresses, be cleared of all dirt, surplus joint material and superfluous material of every description.
(2) 
No sewer main shall be finally joined to the city system until it has been satisfactorily cleaned and flushed.
B. 
Testing. On completion of any sewer or such portion of the same as may be directed and before any connection has been made therewith, the sewer may be tested for leakage or infiltration of groundwater on the order of the inspector. Contractors shall supply all facilities for making such tests. It is the intent of these specifications to have the sewer so constructed that the quantity of infiltration will be kept at a minimum. The allowable leakage shall not exceed a rate of flow of 175 gallons per 24 hours per inch of diameter per 1,000 linear feet of sewer tested. Should any leaky or defective joints or defective constructions be found, they shall be promptly made good; and should any defective pipes or specials be discovered, they shall be replaced with sound pipes or specials in a satisfactory manner and without cost to the city.