Ariz. Admin. Code § 18-16-405

Current through Register Vol. 30, No. 50, December 13, 2024

Section R18-16-405 - Early Response Actions

A. The Department or any person may perform an early response action if the action is initiated prior to selection of a remedy at a site under R18-16-410 and is necessary to:

1. Address current risk to public health, welfare, and the environment;

2. Protect or provide a supply of water;

3. Address sources of contamination; or

4. Control or contain contamination where such actions are expected to reduce the scope or cost of the remedy needed at the site.

B. The method or technology used to implement the early response action shall be selected based upon best engineering, geological, or hydrogeological judgment following engineering, geological, or hydrogeological standards of practice, considering the following information:

1. Best available information characterizing the site;

2. Best available scientific information concerning available remedial methods and technologies; and

3. Best available information regarding whether the technology or method could increase the scope or costs of possible remedies for the site or result in increased risk to public health or welfare or the environment.

C. A written rationale shall be prepared for each early response action explaining how the early response action will achieve the applicable goals in subsection (A) and how the early response action is consistent with A.R.S. § 49-282.06(A). The written rationale shall identify the information used to select the early response action as provided in subsection (B), how that information was considered, and how the selected method or technology was selected. Performance of a remedial investigation or feasibility study shall not be required to select or conduct an early response action.

D. A work plan shall be prepared for each early response action. Each work plan shall include:

1. A description of work to be done, a description of known site conditions, and a plan for conducting the work;

2. A description of community involvement activities for the early response action under R18-16-404; and

3. A schedule.

E. If immediate action is necessary to address a current risk to public health or the environment, to protect a source of water, or to provide a supply of water, the work plan and written rationale may be prepared and the community involvement activities may be conducted after commencement of the early response action.

F. Approval of an early response action under this Section does not constitute approval of the remedy for the site. The remedy for a site where an early response action is conducted shall be selected in accordance with R18-16-406 through R18-16-410. An early response action may be addressed, incorporated and modified as needed in the remedy selected under R18-16-410.

G. After the Department has issued notice under A.R.S. § 49-287.03 for a site or a portion of a site, a person conducting an early response action at a site or portion of a site shall notify the Department, in writing, of the early response action. The notice shall contain a brief description of the early response action and shall be given at least 15 calendar days before the early response action is commenced, or as soon thereafter as practicable depending upon the exigencies of the circumstances. If the early response action has commenced before the Department issues notice under A.R.S. § 49-287.03, written notice of the early response action shall be given within 15 calendar days after the Department's notice is given. After notice of a proposed remedial action plan has been given under R18-16-408(C), an early response action may be initiated only after the Department has approved the early response action.

H. Any person may submit a request to the Department under R18-16-413 to approve an early response action or a work plan for an early response action. The request shall include the work plan and the written rationale for the early response action. The Department shall approve the work plan or early response action if it complies with the following:

1. The requirements of this Section and A.R.S. § 49-282.06(A);

2. Community involvement activities under R18-16-404;

3. The work plan provides for modifications to address unknown or changed conditions; and

4. Any applicable requirements of R18-16-411 and R18-16-412.

I. In considering whether an early response action is necessary to protect or provide a supply of water because a well is threatened by contamination, a well located in the area within 1/4 mile upgradient, 1/2 mile cross-gradient and 1 mile downgradient of the areal extent of contamination at the site shall be presumed to be threatened by the contamination. This presumption may be rebutted by evidence of local hydrology, geology, or geochemistry or by available information regarding the capture zone or rate of flow. In considering whether wells a greater distance from the areal extent of contamination are threatened, any evidence regarding local hydrology, geology, geochemistry, zone of capture, or rate of flow may be considered.

Ariz. Admin. Code § R18-16-405

New Section made by exempt rulemaking at 8 A.A.R. 1491, effective March 4, 2002 (Supp. 02-1).