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The Pennsylvania Code website reflects the Pennsylvania Code changes effective through 54 Pa.B. 2336 (April 27, 2024).

25 Pa. Code § 73.21. Specifications.


§ 73.21. Specifications.

 (a)  Building sewers shall be constructed of a durable material acceptable to the Department or the local agency.

 (b)  The local agency may restrict the type of materials used by code, ordinance or resolution and shall notify the applicant when restrictions are imposed.

 (c)  When the average daily flow of sewage from an establishment is 1,000 gallons or less, building sewers shall be at least 3 inches in diameter unless otherwise specified by local plumbing or building codes. When the average daily flow exceeds 1,000 gpd, all building sewers shall be at least 6 inches in diameter unless otherwise specified by local plumbing or building codes.

 (d)  Cleanouts shall be provided at the junction of the building drain and building sewer.

 (e)  Cleanouts shall be provided at intervals of not more than 100 feet.

 (f)  Bends ahead of the treatment tank shall be limited to 45° or less where possible. If 90° bends cannot be avoided, they shall be made with two 45° bends.

 (g)  The grade of the building sewer shall be at least 1/8 inch per foot; however, the grade of the 10 feet of building sewer immediately preceding the treatment tank may not exceed 1/4 inch per foot.

 (h)  Building sewers shall be constructed with watertight joints, shall be of sufficient strength to withstand imposed loads and installed on material suitable for preventing damage from settling.

 (i)  The building sewer shall be installed to allow continuous venting of the treatment tank through the main building stack unless otherwise specified by local plumbing or building codes.

 (j)  Building sewers shall be connected to treatment tanks by means of watertight mechanical seals or hydraulic grouting. Use of Portland cement grouting is not permitted.


   The provisions of this §  73.21 amended under section 9 of the Pennsylvania Sewage Facilities Act (35 P. S. §  750.9); The Clean Streams Law (35 P. S. § §  691.1—691.1001); and section 1920-A of The Administrative Code of 1929 (71 P. S. §  510-20).


   The provisions of this §  73.21 adopted August 2, 1971, effective August 14, 1971, 1 Pa.B. 1649; amended April 26, 1974, effective May 13, 1974, 4 Pa.B. 817; amended August 30, 1974, effective September 16, 1974, 4 Pa.B. 1805; amended January 21, 1983, effective January 22, 1983, 13 Pa.B. 508; amended November 7, 1997, effective November 8, 1997, 27 Pa.B. 5877. Immediately preceding text appears at serial page (217320).

Cross References

   This section cited in 25 Pa. Code §  73.161 (relating to general).

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