Section R18-16-407. Feasibility Study

A.      The feasibility study is a process to identify a reference rem- edy and alternative remedies that appear to be capable of achieving remedial objectives and to evaluate them based on the comparison criteria to select a remedy that complies with A.R.S. § 49-282.06.

B.       The Department or any person may perform all or any portion of a feasibility study, except that once the Department has issued a notice under A.R.S. § 49-287.03 for a site, a person may perform such work only under a written agreement with the Department. The feasibility study process shall include community involvement procedures in compliance with R18- 16-404 and may be reported concurrently with the remedial investigation. A work plan  shall be developed  and imple- mented for all or any portion of a feasibility study for a site or a portion of a site, as follows:

1.        The work plan shall demonstrate that the work performed will meet the requirements of this Section.

2.        A work plan may be modified as appropriate.

3.        Any person proposing to implement a work plan for all or a portion of a feasibility study shall, before implementing the work plan, notify the Department in writing of the name and address of the working party and a general description of the work being performed. This notice is for the Department’s information only and receipt of the notice shall not constitute approval of the work plan. A person seeking approval of a work plan by the Depart- ment shall proceed under R18-16-413.

C.      For remedies addressing only soils, an analysis of alternative remedies is not required. A feasibility study report shall be prepared that demonstrates:

1.        That the proposed remedy addresses the contaminated soil in a manner that achieves compliance with A.R.S. § 49-152 and 18 A.A.C. 7, Article 2 and will achieve the remedial objectives for the use of the property.

2.        That the proposed remedy was selected based upon best engineering, geological, or hydrogeological judgment following engineering, geological, or hydrogeological standards of practice, considering the following informa- tion:

a.         The remedial investigation;

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

c.         A written analysis explaining how the remedy is consistent with A.R.S. § 49-282.06, including a brief explanation of the comparison criteria as applied to the remedy.

D.      For remedies addressing only landfills that have not and will not impact groundwater or similar sites or portions of sites that have not and will not impact groundwater, and that contain material not subject to A.R.S. § 49-152 and 18 A.A.C. 7, Arti- cle 2, an analysis of alternative remedies is not required. A fea- sibility study report shall be prepared that demonstrates:

1.        That the proposed remedy is designed to prevent human exposure to hazardous substances through the achieve- ment of:

a.         Soil remediation levels established under 18 A.A.C. 7, Article 2, or

b.        Site-specific remediation levels based on a site-spe- cific human health risk assessment, meeting a cumu- lative excess lifetime cancer risk between 1 x 10-4 and 1 x 10-6 and a hazard index no greater than 1. The excess lifetime cancer risk shall be selected by the Department based upon site specific factors including the presence of multiple contaminants, the existence of multiple pathways of exposure, the uncertainty of exposure, and the sensitivity of the exposed population. With prior approval of the Department, a person may achieve a site specific remediation level based on the use of institutional and engineering controls. The approval shall be based in part on the demonstration that the institu- tional and engineering controls will be maintained.

2.        That the proposed remedy was selected based upon best engineering, geological, or hydrogeological judgment following engineering, geological, or hydrogeological standards of practice, considering the following informa- tion:

a.         The remedial investigation;

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

c.         A written analysis explaining how the remedy is consistent with A.R.S. § 49-282.06, including a brief explanation of the comparison criteria as applied to the remedy.

3.        That the proposed remedy will achieve all of the remedial objectives.

E.       For remedies other than provided in subsections (C) and (D), the feasibility study shall provide for the development of a ref- erence remedy and at least two alternative remedies as fol- lows:

1.        The reference remedy and alternative remedies shall be capable of achieving all of the remedial objectives. The reference remedy and each alternative remedy shall con- sist of a remedial strategy under subsection (F) and all remedial measures to be employed. The combination of the remedial strategy and the remedial measures for each

alternative remedy shall achieve the remedial objectives. The reference remedy and any alternative remedy also may include contingent remedial strategies or remedial measures to address reasonable uncertainties regarding the achievement of remedial objectives or uncertain time- frames in which remedial objectives will be achieved. The reference remedy and other alternative   remedies shall be developed and described in the feasibility study report in sufficient detail to allow evaluation using the comparison criteria, but plans at construction level detail are not required. The units of measure set forth in Appen- dix A may be used, as applicable, for comparison of the relevant factors. Where appropriate, the reference remedy and an alternative remedy may incorporate different strat- egies for different aquifers or portions of aquifers.

2.        The reference remedy shall be developed based upon best engineering, geological, or hydrogeological judgment following engineering, geological, or hydrogeological standards of practice, considering the following:

a.         The information in the remedial investigation;

b.        The best available scientific information concerning available remedial technologies; and

c.         Preliminary analysis of the comparison criteria and the ability of the reference remedy to comply with A.R.S. § 49-282.06.

3.        At a minimum, at least two alternative remedies shall be developed for comparison with the reference remedy. At least one of the alternative remedies must employ a reme- dial strategy or combination of strategies that is more aggressive than the reference remedy, and at least one of the alternative remedies must employ a remedial strategy or combination of strategies that is less aggressive than the reference remedy. For the purposes of this Section, a more aggressive strategy is a strategy that requires fewer remedial measures to achieve remedial objectives, a strat- egy that achieves remedial objectives in a shorter period of time, or a strategy that is more certain in the long term and requires fewer contingencies. With the Department’s approval, one of the minimum required alternative reme- dies may use the same strategy as the reference remedy but use different viable technologies or a more intensive use of the same technology utilized in the reference rem- edy.

F.       The remedial strategies to be developed under subsection (E) are listed below. Source control shall be considered as an ele- ment of the reference remedy and all alternative remedies, if applicable, except for the monitoring and no action alterna- tives. A strategy may incorporate more than one remediation technology or methodology, such as a plume remediation strat- egy that consists of a combination of pumping and treating in portions of an aquifer and monitored natural attenuation for other portions of the aquifer. The remedial strategies are:

1.        Plume remediation is a strategy to achieve water quality standards for contaminants of concern in waters of the state throughout the site.

2.        Physical containment is a strategy to contain contami- nants within definite boundaries.

3.        Controlled migration is a strategy to control the direction or rate of migration but not necessarily to contain migra- tion of contaminants.

4.        Source control is a strategy to eliminate or mitigate a con- tinuing source of contamination.

5.        Monitoring is a strategy to observe and evaluate the con- tamination at the site through the collection of data.

6.        No action is a strategy that consists of no action at a site.

G.      Remedial measures necessary for each alternative remedy developed under subsection (E) to achieve remedial objectives or to satisfy the requirements of A.R.S. § 49-282.06(B)(4)(b) shall be  identified  in  consultation with  water providers or known well owners whose water supplies are affected by the release or threatened release of a hazardous substance. In iden- tifying the remedial measures, the needs of the well owners and the water providers and their customers, including the quantity and quality of water, water rights and other legal con- straints on water supplies, reliability of water supplies and any operational implications shall be considered. Such remedial measures may include, but are not limited to, well replace- ment, well modification, water treatment, provision of replace- ment water supplies, and engineering controls. Where remedial measures are relied upon to achieve remedial objec- tives, such remedial measures shall remain in effect as long as required to ensure the continued achievement of those objec- tives. The Department may require financial mechanisms to provide for the cost of implementation of the remedial mea- sures.

H.      The Department or any  person  who conducts a feasibility study by agreement with the Department shall conduct a com- parative evaluation of the reference remedy and the alternative remedies developed under subsection (E). For each alternative, the evaluation shall be reported in a feasibility study report and shall include:

1.        A demonstration that the remedial alternative will achieve the remedial objectives.

2.        An evaluation of consistency with the water management plans of affected water providers and the general land use plans of local governments with land use jurisdiction.

3.        An evaluation of the comparison criteria, including:

a.         An evaluation of the practicability of the alternative, including its feasibility, short and long-term effec- tiveness, and reliability, considering site-specific conditions, characteristics of the contamination resulting from the release, performance capabilities of available technologies, and institutional consider- ations.

b.        An evaluation of risk, including the overall protec- tiveness of public health and aquatic and terrestrial biota under reasonably foreseeable use scenarios and end uses of water. This evaluation shall address:

i.         Fate and transport of contaminants and concen- trations and toxicity over the life of the remedi- ation;

ii.        Current and future land and resource use;

iii.      Exposure pathways, duration of exposure, and changes in risk over the life of the remediation;

iv.       Protection of public health and aquatic and ter- restrial biota while implementing the remedial action and after the remedial action; and

v.        Residual risk in the aquifer at the end of reme- diation.

c.         An evaluation of the cost of the remedial alternative, including the expenses and losses including capital, operating, maintenance, and life cycle costs. The cost analysis may include the analysis of uncertain- ties that may impact the cost of a remedial alterna- tive, analysis of projected water uses and costs associated with use-based treatment, other use impairment costs of water not remediated to water quality standards, and the cost of measures such as alternative water supply or treatment. Transactional costs necessary to implement the remedial alterna- tive, including the transactional costs of establishing

	long-term financial mechanisms, such as trust funds,	C.	Notice of the proposed remedial action plan shall be provided
	for  funding   of  an  alternative  remedy,   shall  be		as follows:
	included in the cost estimate.		1.     At a site where the A.R.S. § 49-287.03 notice has been
	d.     An evaluation of the benefit, or value, of the remedi-		provided, notice shall be provided by the Department in
	ation. This analysis includes factors such as:		accordance with A.R.S. § 49-287.04(b) and the commu-
	i.      Lowered risk to human and aquatic and terres-		nity involvement plan prepared under R18-16-404. If the
	trial biota;		Department intends to seek recovery of costs and conduct
	ii.     Reduced concentration and reduced volume of		a cost allocation proceeding for the site, the notice shall
	contaminated water;		also include the following:
	iii.   Decreased liability; acceptance by the public;		a.      The information required by A.R.S. § 49-287.04(c).
	iv.   Aesthetics; preservation of existing uses;		b.     A  statement   of  costs  incurred  at  the  site  by  the
	v.     Enhancement of future uses; and		Department prior to the date of the notice and pro-
	vi.   Improvements to local economies.		jected future costs for the site.
	e.      A discussion of the comparison criteria, as evaluated		c.      All necessary information regarding the opportuni-
	in relation to each other.		ties to submit costs, object to costs, or respond to
I.	Based upon the evaluation and comparison of the reference		objections to costs under R18-16-409, including a
	remedy and the other alternative remedies developed under		schedule for such submittal, review, objection and
	subsection (E), a proposed remedy shall be developed and		response to objection. The time period for submittal
	described in the feasibility study report. The proposed remedy		of costs shall not be less than 90 calendar days.
	may be the reference remedy, any of the other alternative rem-		d.     If on the basis of new information or investigation
	edies evaluated in the feasibility study, or a different combina-		notice is required to newly-identified parties, the
	tion of remedial strategies and remedial measures that were		notice  sent  under  A.R.S.  §  49-287.04  shall  also
	included in the alternative remedies evaluated in the feasibility		include the information required by this Section.
	study. The feasibility study report shall describe the reasons		2.     At a site where the A.R.S. § 49-287.03 notice has not
	for selection of the proposed remedy, including all of the fol-		been provided, the person who prepared the plan shall
	lowing:		provide  notice  under  R18-16-404.   The  notice  shall
	1.     How  the  proposed   remedy  will  achieve  the  remedial		include  the  information  contained   in  A.R.S.  §   49-
	objectives;		287.04(C).
	2.     How the comparison criteria were considered; and	D.	Any person, other than a person proposing to perform work
	3.     How  the proposed  remedy meets  the  requirements of		under an agreement under A.R.S. § 49-287.03(c), may submit
	A.R.S. § 49-282.06.		a  proposed   remedial  action  plan   to  the  Department   for
J.	Any person, other than a person proposing to perform work		approval under R18-16-413. The plan may be accompanied by
	under an agreement under A.R.S. § 49-287.03(C), may submit		a request for a determination of whether cost recovery by the
	a request in compliance with R18-16-413 for the Department		Department may be appropriate under A.R.S. § 49-287.02. If
	to approve a work plan or a report for all or any portion of a		the Department determines that cost recovery by the Depart-
	feasibility study. The Department shall approve a work plan		ment is not appropriate, notice shall be provided under subsec-
	for a feasibility study if the request shows that the work will		tion (C)(2).

comply with this Section, community involvement activities will be performed in compliance with R18-16-404, and the work plan provides for modifications to comply with this Sec- tion. The Department shall approve a feasibility study report if the feasibility study complies with this Section and community involvement activities have been conducted under this Article.

Historical Note

New Section made by exempt rulemaking at 8 A.A.R.

1491, effective March 4, 2002 (Supp. 02-1).