1 Pa. Code § 35.36
A participant may file an answer to a petition to intervene, and in default thereof, may be deemed to have waived an objection to the granting of the petition. If made, answers shall be filed within 10 days after the date of service of the petition, but no later than 5 days prior to the date set for the commencement of the hearing, if any, unless for cause the agency with or without motion shall prescribe a different time.
1 Pa. Code § 35.36
This section cited in 1 Pa. Code § 35.31 (relating to notice and action on petitions to intervene); 7 Pa. Code §179.14 (relating to answers to complaints, petitions, motions and other filings requiring a response); 7 Pa. Code §179.17 (relating to intervention); 12 Pa. Code §11.9 (relating to answers to complaints and petitions); 25 Pa. Code §1021.81 (relating to intervention); 34 Pa. Code §111.15 (relating to no other pleadings allowed); 34 Pa. Code §131.33 (relating to answers except answers to petitions for joinder and challenge proceedings); 34 Pa. Code §131.121 (relating to penalty proceedings initiated by a party); 34 Pa. Code §225.8 (relating to petition to intervene); 40 Pa. Code §17.13 (relating to protests/intervention procedure); 52 Pa. Code §5.66 (relating to answers to petitions to intervene); 52 Pa. Code §1005.45 (relating to answers to petitions to intervene); 55 Pa. Code §41.72 (relating to answers to petitions to intervene); 58 Pa. Code §493a.5 (relating to answers to complaints, petitions, motions and other filings requiring a response); 58 Pa. Code §493a.12 (relating to intervention); 61 Pa. Code §703.2 (relating to petition content); and 67 Pa. Code §491.6 (relating to notice and conduct of hearing).