815 KAR 20:130. House sewers and storm water piping; methods of installation.

 

      RELATES TO: KRS 318.010, 318.015, 318.130, 318.150, 310.200

      STATUTORY AUTHORITY: KRS 318.130

      NECESSITY, FUNCTION, AND CONFORMITY: KRS 318.130 requires the office, after approval by the State Plumbing Code Committee, to promulgate an administrative regulation establishing the Kentucky State Plumbing Code regulating plumbing, including the methods and materials that may be used in Kentucky for the construction of house sewers and storm water piping. This administrative regulation identifies the materials and methods of installation that may be used in the construction of house sewers or storm water piping.

 

      Section 1. Independent System. The drainage and plumbing system of new building and of a new work installed in an existing building shall be separate and independent of other buildings except as otherwise provided in this administrative regulation. A building shall have an independent connection with either a public or private sewer or sewer system.

 

      Section 2. Exception. If a building stands in the rear of other buildings or on an interior lot and a sewer connection cannot be made available to the rear building through an adjoining alley, court, yard, or driveway, the sewer from the front building may be extended to the rear building and it shall be considered as one (1) sewer. This exception shall not apply to corner lots if a sewer connection is available from the street or alley or to a new or existing building which abuts a street or alley.

 

      Section 3. Connection with Private Sewage Disposal System. If a sewer is not available, the house drain from a building shall connect with an approved private sewage disposal system.

 

      Section 4. Excavations. An excavation made for the installation of a house sewer shall be open trench work, and the trenches shall be kept open until the piping has been inspected, tested, and approved.

 

      Section 5. Depth of Sewer at the Property Line. (1) The sewer at the property line shall be at a sufficient depth to properly serve a plumbing connection installed in the basement of a building.

      (2)(a) A house sewer shall be laid on a grade of not less than one-eighth (1/8) inch nor more than one-fourth (1/4) inch per foot.

      (b) A sewer shall have at least an eighteen (18) inch cover.

      (c) Sewer piping installed under property subject to vehicular traffic (e.g., a driveway, parking lot, or similar location) shall have at least a twenty-four (24) inch cover unless constructed of cast iron piping. If less than a twenty-four (24) inch cover is available, sewer piping shall be encased in a minimum of six (6) inches of concrete on each side and the top.

      (d) A sewer shall be backfilled by hand and tamped six (6) inches above the piping, or filled with six (6) inches grillage above the piping.

      (e) Each joint in cast iron and vitrified clay pipe shall be constructed to comply with 815 KAR 20:060, Sections 4 and 5.

 

      Section 6. New House Sewer Connections. A house sewer installed where a private sewerage system has been discarded may connect to the house drain, if the existing plumbing system meets the State Plumbing Code.

 

      Section 7. Materials for House Sewers. A house sewer or combined sewer shall be made of the following:

      (1) Extra heavy cast iron pipe;

      (2) Service weight cast iron;

      (3) Aluminum;

      (4) Vitrified clay;

      (5) Concrete;

      (6) Coextruded composite PVC pipe produced and labeled ASTM F-1488;

      (7) PVC or ABS plastic pipe schedules 40 and 80;

      (8) Cellular core PVC produced and labeled as ASTM F-891;

      (9) Cellular core ABS produced and labeled as ASTM 628;

      (10) Truss pipe;

      (11) Extra heavy SDR 35 pipe;

      (12) Type PS 46, PVC in sizes four (4) inches through fifteen (15) inches produced and labeled as ASTM F 789-82;

      (13) PVC ribbed pipe produced and labeled as ASTM 795; or

      (14) Polyethylene pipe produced and labeled as ASTM F-714.

 

 

      Section 8. Material for Storm Sewers Inside Buildings. (1) A storm sewer inside of a building extending to a point two (2) feet outside a building in sizes eight (8) inches and smaller shall be made of the following:

      (a) Cast iron pipe;

      (b) Aluminum; or

      (c) Schedule 40 ABS or PVC DWV pipe or PVC pipe produced and labeled as ASTM F-1488.

      (2) A storm sewer in a size of ten (10) inches and larger shall be made in the following:

      (a) Cast iron;

      (b) Aluminum;

      (c) Schedule 40 ABS or PVC DWV pipe;

      (d) SDR 35;

      (e) Vitrified clay or concrete conforming to appropriate commercial specifications with approved joints; or

      (f) Polyethylene pipe produced and labeled as ASTM F-714.

      (3) Primary and secondary roof drains shall comply with the following requirements:

      (a) Roof drains shall have strainers extending not less than four (4) inches above the surface of the roof immediately adjacent to the roof drain. Strainers shall have an available area not less than one and one-half (1 1/2) times the area of the conductor or leader to which the drain is connected:

      (b) Roof drain strainers for use on sun decks, parking decks, and similar areas that are normally services and maintained may be of the flat surface type, installed level with the deck, with an available inlet area not less than two (2) times the area of the conductor or leader to which the drain is connected;

      (c) Secondary (emergency) roof drains or scuppers shall be provided where the roof perimeter construction allows ponding if the primary roof drains become blocked;

      (d) Separate systems required. Secondary roof drain systems shall have piping and point of discharge separate from the primary system. Discharge shall be above grade in a location which would normally be observed by the building occupants or maintenance personnel; and

      (e) Primary and secondary drains must be sized in accordance with 815 KAR 20:130, Section 11, of the Kentucky State Plumbing Code.

 

      Section 9. Change of Direction. A change in direction of a sewer shall be made only with:

      (1) Long curves;

      (2) Forty-five (45) degree wyes;

      (3) Half wyes;

      (4) Quarter, sixth, eighth or sixteenth bends; or

      (5) Sanitary tees installed on their back or on their sides at an angle of not more than forty-five (45) degrees.

 

      Section 10. Size of House Sewers and Horizontal Branches. The minimum size of a house sewer shall not be less than four (4) inches nor less than that of the house drain. A house sewer receiving a branch shall be sized in the same manner as a house drain. The house drains shall be installed in accordance with 815 KAR 20:090.

 

      Section 11. Size of Storm Systems. The required size of a storm sewer shall be determined on the basis of the total drained area in horizontal projection in accordance with table in this section. A storm sewer shall not be laid parallel to or within two (2) feet of a bearing wall. The storm sewer shall be laid at a sufficient depth to protect it from freezing.

*The calculations in this table are based on a rate of rainfall of four (4) inches per hour.

 

      Section 12. Combined Storm and Sanitary Sewer System. If a combined sewer system is used, the required size of the house drain or house sewer shall be determined by multiplying the total number of fixture units carried by the drain or sewer by the conversion factor corresponding to the drained area, and the total fixture units, adding the product to the drained area and applying the sum from the table for storm water sewers in Section 11 of this administrative regulation. A combined house drain or house sewer shall not be less than four (4) inches in diameter, and a combined house drain or house sewer shall not be smaller in size than that required for the same number of fixture units or for the same roof area in separate systems.

 

CONVERSION FACTORS FOR COMBINED STORM AND SANITARY SYSTEM
Number of fixture units on sanitary system
Drained roof area in square feet	Up to 6	7 to 18	19 to 36	37 to 60	61 to 96	97 to 144	145 to 216	217 to 324
Up to 120	180	105	60	45	30	22	18	15
121 to 240	160	98	57	43	29	21	17.6	14.7
241 to 480	120	75	50	39	27	20	16.9	14.3
481 to 720	75	62	42	35	24	18	15.4	13.2
721 to 1,080	54	42	33	29	20	15	13.6	12.1
1,081 to 1,620	30	18	16	15	12	11.5	11.1	10.4
1,621 to 2,430	15	12	11	10.5	9.1	8.8	8.6	8.3
2,431 to 3,645	7.5	7.2	7.0	6.9	6.6	6.5	6.4	6.3
3,646 to 5,460	2.0	2.4	3.0	3.3	4.1	4.2	4.3	4.4
5,461 to 8,190	0	2.0	2.1	2.2	2.3	2.4	2.5	2.6
8,191 to 12,285	0	0	2.0	2.1	2.1	2.2	2.3	2.3
12,286 to 18,420	0	0	0	2.1	2.1	2.1	2.2	2.2
18,421 to 27,630	0	0	0	0	2.0	2.1	2.2	2.2
27,631 to 40,945	0	0	0	0	0	2.0	2.1	2.2
40,946 to 61,520	0	0	0	0	0	0	2.0	2.1
Over 61,520	0	0	0	0	0	0	0	2.0

 

Number of fixture units on sanitary system
Drained roof area in square feet	325 to 486	487 to 732	733 to 1098	1,099 to 1644	1,645 to 2466	2,467 to 3702	3,703 to 5556	Over 5556
Up to 120	12	10.2	9.2	8.4	8.2	8.0	7.9	7.8
121 to 240	11.8	9.9	9.1	8.3	8.1	8.0	7.9	7.8
241 to 480	11.5	9.7	8.8	8.2	8.0	7.9	7.8	7.7
481 to 720	10.8	9.2	8.6	8.1	7.9	7.9	7.8	7.7
721 -1,080	10.1	8.7	8.3	8.0	7.8	7.8	7.7	7.6
1,081 - 1,620	9.8	8.4	8.1	7.9	7.7	7.7	7.6	7.5
1,621 - 2,430	8.0	7.9	7.8	7.7	7.6	7.5	7.4	7.4
2,431 - 3,645	6.2	6.3	6.4	6.4	6.8	7.0	7.1	7.2
3,646 - 5,460	4.5	4.7	5.0