US lawIllinoisRegulationsTitle 77 — PUBLIC HEALTHCHAPTER I: DEPARTMENT OF PUBLIC HEALTHSUBCHAPTER r: WATER AND SEWAGEPart 890 — ILLINOIS PLUMBING CODESubpart H890.102077 Ill. Adm. Code 890.1020Material and SizeYear: 2026Length: 29 wordsOfficial source Section 890 Section 890.1020 Material and Size Indirect waste pipe sizes shall be the same as the fixture outlets, but at least three-fourths ( 3 / 4 ) inch.Previous77 Ill. Adm. Code 890.1010Next77 Ill. Adm. Code 890.1030