D.C. Mun. Regs. tit. 20, r. 20-2503
Pursuant to the Brownfields Revitalization Amendment Act of 2000, effective April 8, 2011 (D.C. Law 18-369; D.C. Official Code §§ 8-631et seq.), in the event of an application, spill, or release of a pesticide, or an alleged or threatened violation of the law and rules described in § 2500.1, the District Department of the Environment (Department) may, under the following circumstances, enter any place or vehicle to perform, or cause to be performed, any responsive or corrective action necessary to protect public health, safety, or welfare, or the environment:
Except as provided in § 2503.3, the Department shall provide notice in writing of the Department's intent to enter the premises or vehicle to take responsive or corrective action to the owner, applicator, dealer, operator, supervisor, employee, or agent in charge at least seven (7) days before commencing work, and shall serve the notice personally or by first class mail, or where such service cannot be accomplished, by publication or posting.
When an application, spill, or release of a pesticide, or an alleged or threatened violation of the law and rules described in § 2500.1, creates an imminent threat to public health, safety, or welfare, or the environment necessitating response or corrective action, and the emergency nature of the situation makes it impractical to give prior notice as described in § 2503.2, the Department may provide notice by conspicuously posting the notice on the property at the earliest time feasible, before commencing work.
D.C. Mun. Regs. tit. 20, r. 20-2503