40 CFR §267.74

1. (a)You must furnish all records, including plans, required under this part upon the request of any officer, employee, or representative of EPA who is duly designated by the Administrator, and make them available at all reasonable times for inspection.
2. (b)The retention period for all records required under this part is extended automatically during the course of any unresolved enforcement action involving the facility or as requested by the Administrator.