A. 
Load on drainage piping. The load on drainage system piping shall be computed in terms of drainage fixture units in accordance with Table 860-132A and § 860-132A.
Table 860-132A
Fixture Unit Values for Various Plumbing Fixtures and Minimum Trap Size
Plumbing Fixtures
Fixture Unit Value
Minimum Trap Size In Inches
Automatic clothes washer (when connected to drainage system)
3
2
Bathtub (with or without overhead shower)
2
1 1/2
Bedpan washer
8
3
Bidet
2
1 1/2
Combination sink & tray (separate traps for each compartment)
3
1 1/2
Combination sink & tray with food waste grinder (separate traps for each compartment)
4
1 1/2
Dental unit for cuspidor
1
1 1/2
Dental lavatory
1
1 1/4
Drinking fountain
1
1 1/4
Dishwasher — commercial
3 or 5
2 or 3
Dishwasher — domestic
2
1 1/2
Floor drain (above ground)
4
3
Floor drain (below ground)
5
4
Floor drain (car wash or similar functions)
6
4
Kitchen sink — domestic
2
1 1/2
Kitchen sink — domestic, with food waste grinder
3
1 1/2
Kitchen sink — domestic, double bowl (separate traps for each compartment)
3
1 1/2
Kitchen sink — domestic — double bowl with food waste grinder (separate traps for each compartment)
4
1 1/2
Lavatory, common
1
1 1/4
Lavatory (barber shop, beauty parlor or surgeons)
2
1 1/2
Lavatory, multiple type (wash fountain or wash sink)
2
2
Laundry tray (1 or 2 compartment)
2
1 1/2
Laundry tray (3 to 5 compartments)
3
2
Shower stall (single)
2
2
Shower stalls (group or gang type, above ground)
2 per head
3
Shower stalls (group or gang type, below ground)
2 per head
4
Sink — surgeons
3
1 1/2
Sink — flushing rim type, flush valve supplied
6
3
Sink — service type with trap combined
4
3
Sink — service type, ordinary
2
2
Sink — service type, janitors style, floor receptor (above ground)
4
2, 3 or 4
Sink — service type, janitors style, floor receptor (below ground)
4
4
Sink — commercial (pot, scullery, or similar type)
4
2
Sink — commercial (with food grinder unit)
4
2
Urinal (pedestal, syphon jet)
8
3
Urinal (wall hung blowout type, flush valve supplied)
6-8
2-3
Urinal — trough (each 2 ft. section)
2
1 1/2
Urinal (wall hung siphon jet)
4
2
Urinal (wall lip type, flush tank or self-closing valve)
2
1 1/2
Urinal (stall type — existing only)
4
2
Water closet tank operated
4
3
Water closet valve operated
8
3
Type of Fixture
Fixture Unit Value
Unlisted fixture drain or trap size
1 1/4 inch or less
1
1 1/2 inch or less
2
2 inches or less
3
2 1/2 inches or less
4
3 inches or less
5
4 inches or less
6
B. 
Values for continuous flow. Fixture unit values for continuous or semicontinuous flow into a drainage system, such as from a pump, sump ejector, air conditioning equipment or similar device shall be computed on the basis of two fixture units for each gallon per minute of flow.
Pipe sizes shall be determined from Table 860-133A and Table 860-133B on the basis of drainage load computed from Table 1101.1 and Section 1101.2.
Table 860-133A
Maximum Loads on Building Drains and Sewers
Diameter of Drain
(inches)
Maximum Number of Fixture Units that may be connected to any portion1 of the building drain or the building sewer
Fall per Foot
1/16"
1/8"
1/4"
1/2"
*1 1/4"+
N.P.
N.P.
1
1
*1 1/2"+
N.P.
N.P.
3
4
*2"+
N.P.
N.P.
21
26
*2 1/2"+
N.P.
N.P.
24
31
*3"
N.P.
N.P.
27 (2)
36 (2)
4"
N.P.
180
216
250
5"
N.P.
390
480
575
6"
N.P.
700
840
1,000
8"
1,400
1,600
1,920
2,300
10"
2,500
2,900
3,500
4,200
12"
3,900
4,600
5,600
6,700
15"
7,000
8,300
10,000
12,000
NOTES:
1
Includes branches of building drain.
*
When building drain is above basement floor.
+
No water closets permitted.
(2)
Not over two water closets.
N.P.
Not Permitted.
Table 860-133B
Maximum Loads on Soil and Waste Stacks and Branches of Stacks
Diameter of Drain
(inches)
Any Horizontal (1) Fixture Branch
One Stack of 3 stories in Height — Includes 1 & 2 Story Bldgs.
More than 3 stories in height
Total for stack
Total at one Story or Branch Interval
1 1/4" Waste
1
2
2
1
1 1/2" Waste
3
4
8
2
2" Waste
6
10
24
6
2 1/2" Waste
12
20
42
9
3" Soil and/or Waste
20 (2)
30 (3)
60 (3)
16 (2)
4" Waste
160
240
500
90
5" Waste
360
540
1,100
200
6" Waste
640
960
1,900
350
8" Waste
1,400
2,200
3,600
600
10" Waste
2,500
3,800
5,600
1,000
12" Waste
3,900
6,000
8,400
1,500
NOTES:
(1)
Does not include branches of the building drain.
(2)
Not over two water closets.
(3)
Not over six water closets.
A. 
All soil and waste stacks shall extend in a vertical line from the highest to the lowest horizontal branch or fixture connected thereto through the roof and shall not be reduced in size, except that where offsets in vertical stacks are unavoidable such increase in sizing as outlined in § 860-138B of this chapter shall not be considered as a reduction in stacks. Also first floor water closets, the location of which, prevents a connection to available soil stacks, may connect to the building drain and be relieved by a proper size relief vent.
B. 
This procedure shall not be considered as a reduction in the soil stack, however, all soil stacks extending beyond the first floor level provided to receive the discharge of water closets or similar fixtures shall not be reduced in size. No soil or waste stack shall be smaller in size than the attending vent stack, nor shall any soil or waste stack be smaller in size than the largest horizontal branch connected thereto, except that a four by three water closet connection shall not be considered as a reduction in pipe size.
Any building or structure containing at least one water closet or pedestal urinal shall have a building drain installed with at least one stack vent or vent stack carried full size through the roof not less than three inches in diameter. No soil, waste or vent pipe shall be installed on the outside of a new building. Any building or structure having a sewer connection with a public or private sewer which has a drainage system installed to receive discharge from floor drainage only, will require a minimum of two inch relief vent which must be extended through the roof of the building from the rear of the main building drain and be of a larger size where warranted. Building drains installed for roof drainage only will not require a relief vent.
When provision is made for the future installation of fixtures, those provided for shall be considered in determining the required sizes of drain and vent pipes. Where future connections are left in the roughing of soil and waste stacks, vent connections must also be provided, and all such future connections shall be terminated with a plugged fitting or fittings so arranged as to form no dead end.
Sanitary drainage systems installed underground or below a basement or cellar floor shall be four inches in diameter, except;
A. 
Traps used for bath tubs and individual showers may be 1 1/2 or two inches respectively.
B. 
Waste lines extending at least six inches above the finished floor provided for clear water wastes identified in § 860-128D, G and H terminated with proper fittings in the vertical piping between a floor drain and floor drain trap. Minimum size 1 1/2 inches.
C. 
In residential installations, waste and/or soil pipe three inch, two inch, and 1 1/2 inch may be installed within the perimeter of a toilet room, and three inch and two inch installed as branches of the building drain provided the developed length does not exceed 10 feet from the main building drain. (NOTE: Use of cast iron two inches and smaller shall be prohibited.)
A. 
Offsets of 45° or less.
(1) 
An offset in a vertical stack, with a change of direction of 45° or less from the vertical, may be sized as a straight vertical stack.
(2) 
On buildings with four or more stories above an offset, no horizontal branch shall connect to the stack within two feet above or below the offset, or may connect with the travel portion of the offset at least two feet from either change in direction.
B. 
Offsets of more than 45°. A stack with an offset of more than 45° from the vertical shall be sized as follows:
(1) 
The portion of the stack above the offset shall be sized as for a regular stack based on the total number of fixture units above the offset, except that the portion of the stack above the offset shall not be smaller in size than required for straight vertical stacks based upon total fixture unit count for the entire stack.
(2) 
The offset shall be sized as for a building drain Table 860-133A, "Maximum Loads on Building Drains and Sewers".
(3) 
The portion of the stack below the offset shall be sized as for the offset or based on the total number of fixture units on the entire stack, whichever is the larger. A relief vent for the offset shall be installed in accordance with Article XIII, § 860-147E, and in no building with four or more stories above an offset, shall the horizontal branch of fixtures on a floor directly above an offset connect to the stack at that level, but shall connect with the horizontal portion of the offset at least two feet from either change in direction, or it shall connect at least two feet below the offset. (See illustration.[1])
[1]
Editor's Note: The illustration is on file in the Health Department office.
C. 
Above highest branch. An offset above the highest horizontal branch is an offset in the stack-vent and shall be considered only as it affects the developed length of the vent. But no such offset shall be made in the stack-vent at an angle greater than 45° unless suitable provisions are made to prevent the accumulation of rust, scale or condensate.
D. 
Below lowest branch. In the case of an offset in a soil or waste stack below the lowest horizontal branch, there shall be no change in diameter required if the offset is made at an angle of not greater than 45°. If such an offset is made at an angle greater than 45° to the vertical, the required diameter of the offset and the stack below it shall be determined as for a building drain Table 860-133A. No relief vent will be required for an offset in a stack when such offset is located at least ten feet below the lowest horizontal branch connected to the stack, however, the attending vent stack may be started or located at this position. (See attached illustration for this location.[2])
[2]
Editor's Note: The illustration is on file in the Health Department office.
A. 
Slope of horizontal drainage piping. Horizontal drainage piping shall be installed in uniform alignment at uniform slopes not less than 1/4 inch per foot for three inch diameter and less, and not less than 1/8 inch per foot for diameters of four inches or more. Where conditions do not permit building drains and sewers to be laid with slope as great as that specified, a lesser slope may be permitted as determined from Table 860-133. A provided computed velocity is at least two feet per second.
B. 
Depth of horizontal building drains. Horizontal building drains inside building (at highest point) a minimum 12" from finished floor to flow line of pipe shall be required on all underground sanitary building drains, where sufficient fall is available.
Fittings used to change direction. Change in direction in drainage piping shall be made by the appropriate use of 45-degree wyes, long or short sweep bends, sixth, eighth, or sixteenth bends, or by a combination of these or equivalent fittings. Single sanitary tees may be used in drainage lines only where the direction of flow is from the horizontal to the vertical. Quarter bends may be used in drainage lines where the direction of flow is from the horizontal to the vertical, or vertical to the horizontal.
A. 
Prohibited fittings. No fitting or connection which has an enlargement chamber or recess with a ledge or shoulder, or reduction in pipe area shall be used. No running threads, bends, or saddles shall be used. No drainage, or vent piping shall be drilled or tapped unless otherwise permitted by the Administrative Authority.
B. 
Heel or side-inlet bends. A heel or side-inlet quarter bend may be used provided, the heel or side inlet is a sufficient distance above the flow line of the fitting as determined by the Administrative Authority.
C. 
Obstruction to flow. No fitting, connection, device, or method of installation which obstructs or retards the flow of water, waste, sewage, or air in the drainage or venting system in an amount greater than the normal frictional resistance to flow, shall be used unless it is indicated as acceptable in this code, or is approved by the Administrative Authority as having a desirable and acceptable function and as of ultimate benefit to the proper and continuing functioning of the plumbing system, the enlargement of a three-inch closet bend or stub to four inches shall not be considered an obstruction, provided the horizontal flow line of insert is continuous without forming a ledge.
In the installation or removal of any part of a drainage system, dead ends shall be avoided except where necessary to extend a cleanout so as to be accessible.
A. 
All building drains shall be discharged into the sewer by gravity flow. When differences exist in the elevation of the sewer and the main building drain prohibiting the flow by gravity, a variance may be granted pursuant to § 860-6 by the Director, but shall require, in addition to any other requirements, that the alternate system meet all requirements of this chapter. Any alternate system shall discharge into a tightly covered and vented sump from which the liquid shall be lifted and discharged into the building gravity drainage system by automatic pumping equipment or by any equally efficient method approved by the Administrative Authority.
B. 
Any building having a single lower level, with fixtures or drains discharging sewage or liquid waste below the normal grade of the gravity system may use a sump as an auxiliary method to discharge from the single below grade level only. The use of an auxiliary sump will not require a variance but must be approved by the Administrative Authority.
C. 
Design of sumps. Sump and pumping equipment shall be so designed as to discharge contents accumulated in the sump during the cycle of emptying operation and the storage of drainage in a sump or ejector shall not exceed 12 hours. Sumps in other than one or two-family residences receiving the discharge of six or more water closets shall be provided with duplex pumping-equipment. The sump vent shall be of proper size to meet the venting requirements as outlined in Article XIII, § 860-159, "Venting of Sumps and Sewers". Sumps receiving the discharge of clear water, such as rain water, subsoil or seepage drainage, (excluding drainage from sanitary fixtures), will not require a vent. A back water valve and a gate valve shall be installed in the discharge line of every sump or receiving tank.
D. 
Construction of sanitary sumps. Every sump or receiving tank, receiving the discharge of plumbing fixtures or sanitary drains, shall be constructed of approved material and the lid or cover shall be gas and air tight.