The house drainage system shall be so designed that there will be an adequate circulation of air in all pipes and no danger of siphonage, aspiration or forcing of trap seals under conditions of ordinary use.
Del. Code tit. 16, § 7921
Adequate air circulation
47 Del
Official source: Delaware Code Online. Reproduced from public-domain Delaware statutes; confirm against the official source for the current text. Not legal advice.