Ariz. Admin. Code § R18-13-1002 - Location Restrictions

A. 40 CFR 257.60 through 40 CFR 257.64, revised as of December 14, 2020 (and no future editions) are incorporated by reference, modified by the following subsections, and on file with ADEQ.

B. In addition to the location requirements in 40 CFR 257.62(a), new CCR surface impoundments and all lateral expansions of CCR surface impoundments shall not be located within 60 meters (200 feet) of the outermost damage zone of a fault that has had displacement in either Holocene or Late Pleistocene time unless the owner or operator demonstrates by the date specified in § 257.62(c)(2) that an alternative setback distance of less than 60 meters (200 feet) will prevent damage to the structural integrity of the CCR impoundment.

C. In addition to the requirements in 40 CFR 257.63(a), the following requirements are added:

1. For a new or lateral expansion of a CCR surface impoundment, the owner or operator shall submit a review of the seismic or earthquake history of the area around the surface impoundment within a radius of 100 miles to establish the relationship of the site to known faults and epicenters. The review shall include any known earthquakes and the epicenter locations and magnitudes of the earthquakes.

2. For a new or lateral expansion of a CCR surface impoundment, the owner or operator shall identify the location of active or potentially active faults that have experienced Holocene or Late Pleistocene displacement within a radius of 100 miles of the site.

3. For a new or lateral expansion of a high or significant hazard potential CCR surface impoundment, the owner or operator shall design the impoundment to withstand the maximum credible earthquake or the maximum horizontal acceleration, whichever is greater.

D. In addition to the requirements in 40 CFR 257.64, the owner or operator shall not construct a new CCR surface impoundment or a CCR surface impoundment lateral expansion on active faults, as defined by § 257.62(a), collapsible soils, dispersive soils, sinkholes, fissures, or soils with the potential for subsidence, unless the owner or operator demonstrates that the CCR surface impoundment can safely withstand the anticipated offset or other unsafe effects on the CCR surface impoundment.

E. Subsections (B), (C), and (D) of this Section are based on Arizona dam safety standards in existence on July 12, 2024, are additional to those in 40 CFR 257, subpart D, as incorporated in this Article, and do not apply to:

1. CCR surface impoundments with a maximum height of less than 6 feet, regardless of storage capacity;

2. CCR surface impoundments with a maximum height of between 6 and 25 feet and a storage capacity of less than 50 acre-feet; or

3. CCR surface impoundments with a maximum height greater than 25 feet and a storage capacity of 15 acre-feet or less.

Notes

Ariz. Admin. Code § R18-13-1002

New section made by final rulemaking at 31 A.A.R. 1363, effective 6/1/2025.