1. A. The requirements in this Section are additional to those in 40 CFR 257, subpart D, as incorporated in this Article, and do not replace or negate any requirement of 40 CFR 257, subpart D, as incorporated herein.

2. B. Applications to Construct, Reconstruct, Repair, Enlarge, or Alter a High or Significant Hazard Potential CCR Surface Impoundment. An application to construct, reconstruct, repair, enlarge, alter or laterally expand a high or significant hazard potential CCR surface impoundment shall include the following prepared by or under the supervision of a qualified professional engineer:

   1. 1. All construction drawings as prescribed in subsection (G)(1) of this Section.
   2. 2. All construction specifications as prescribed in subsection (G)(2) of this Section.
   3. 3. An engineering design report that includes information needed to evaluate all aspects of the design of the CCR surface impoundment and appurtenances, including references with page numbers to support any assumptions used in the design, as prescribed in subsection (G)(3) of this Section. The engineering design report shall recommend a safe storage level for existing CCR surface impoundments being reconstructed, repaired, enlarged, or altered.
   4. 4. A construction quality assurance plan describing all aspects of construction supervision.

3. C. Applications to Breach or Remove a High or Significant Hazard Potential CCR Surface Impoundment Embankment.

   1. 1. An application shall include plans for the excavation of the embankment down to the level of the natural ground at the maximum section. Upon approval of the Director, additional breaches may be made. This provision shall not be construed to require more than total removal of the embankment regardless of the flood magnitude. The breach or breaches shall be of sufficient width to pass the greater of:

      1. a. The 100-year flood at a depth of less than 5 feet, or
      2. b. The 100-year flood at a normal flood depth of not more than 2 feet at a distance of 2,000 feet downstream of the CCR surface impoundment.
   2. 2. The sides of each breach shall be excavated to a slope ratio that is stable and not steeper than 1 horizontal to 1 vertical.
   3. 3. Each breach shall be designed to prevent silt or CCR that has previously been deposited on the reservoir bottom and the excavated material from the breach from washing downstream.
   4. 4. Before breaching the CCR surface impoundment embankment, the reservoir shall be emptied in a controlled manner that will not endanger lives or damage downstream property. The applicant shall obtain approval from the Director for the method of breaching or removal.

   5. 5. An application to breach or remove a high or significant hazard potential CCR surface impoundment embankment shall include the following prepared by or under the supervision of a qualified professional engineer:

      1. a. The construction drawing or drawings for the breach or removal of a CCR surface impoundment, including the location, dimensions, and lowest elevation of each breach.
      2. b. A construction quality assurance plan describing all aspects of construction supervision.

   6. 6. Reduction of a high or significant hazard potential CCR surface impoundment to a size less than subsection (H)(1), (H)(2) or (H)(3) of this Section shall be approved pursuant to R18-13-1017 under the following circumstances:

      1. a. The owner or operator shall submit a completed application and construction drawings for the reduction and the appropriate specifications, prepared by or under the supervision of a qualified professional engineer.
      2. b. The construction drawings and specifications shall contain sufficient detail to enable a contractor to bid on and complete the project.
      3. c. The plans shall comply with all requirements of this subsection (C) except that the breach is not required to be to natural ground.
      4. d. Upon completion of the reduction to a size less than subsection (H)(1), (H)(2) or (H)(3) of this Section, the qualified professional engineer shall file as constructed drawings and specifications with the Department.

4. D. Applications to Construct, Reconstruct, Repair, Enlarge, Alter, Breach, or Remove a Low Hazard Potential CCR Surface Impoundment.

   1. 1. An application package to construct, reconstruct, repair, enlarge, or alter a low hazard potential CCR surface impoundment shall include the following prepared by or under the supervision of a qualified professional engineer:

      1. a. Files of all construction drawings as prescribed by subsection (G)(1) of this Section.
      2. b. Files of all construction specifications as prescribed by subsection (G)(2) of this Section.
      3. c. An engineering design report that includes information needed to evaluate all aspects of the design of the CCR surface impoundment and appurtenances, including references with page numbers to support any assumptions used in the design, as prescribed in subsection (G)(3) of this Section.

   2. 2. An application package for the breach or removal of a low hazard potential CCR surface impoundment embankment shall include the following:

      1. a. A completed application shall contain the following information:

         1. i. The name and address of the owners and operators of the CCR surface impoundment.
         2. ii. A description of the proposed removal.
         3. iii. The proposed time for beginning and completing the removal.

      2. b. A statement by a qualified professional engineer demonstrating both of the following:

         1. i. That the CCR surface impoundment embankment will be excavated to the level of natural ground at the maximum section; and

         2. ii. That the breach or breaches will be of sufficient width to pass the greater of:

            1. (1) The 100-year flood at a depth of less than 5 feet, or
            2. (2) The 100-year flood at a normal flood depth of not more than 2 feet at a distance of 2,000 feet downstream of the CCR surface impoundment embankment,
            3. (3) This paragraph (ii) shall not be construed to require more than a total removal of the CCR surface impoundment embankment regardless of flood magnitude.
         3. iii. That the sides of the breach will be excavated to a slope ratio that is stable and not steeper than 1 horizontal to 1 vertical.

   3. 3. Within 90 days after completing removal of a low hazard potential CCR surface impoundment embankment, the owner or operator shall file the following:

      1. a. A brief completion report, including a description of the causes for any changes or deviations from the approved application package prepared by the qualified professional engineer who supervised the construction, in accordance with A.R.S. Title 32, Chapter 1. The qualified professional engineer shall certify that the as removed drawings and the report accurately represent the actual removal of the CCR surface impoundment embankment.
      2. b. As-removed drawings prepared and sealed by the qualified professional engineer who supervised the removal. The owner or operator and the qualified professional engineer shall maintain a record of the drawings.

5. E. Construction of a High, Significant, or Low Hazard Potential CCR surface impoundment.

   1. 1. Before commencement of construction activities, the owner or operator shall invite to a pre-construction conference all involved regulatory agencies, the prime contractor, and all subcontractors. At this meeting the Department shall identify, to the extent possible, the key construction stages at which an inspection will be made. At least 48 hours before each key construction stage identified for inspection, the owner or operator or the owner’s qualified professional engineer shall provide notice to the Department.
   2. 2. The owner or operator’s qualified professional engineer shall oversee construction of a new CCR surface impoundment or the lateral expansion reconstruction, repair, enlargement, alteration, breach, or removal of an existing CCR surface impoundment.
   3. 3. A qualified professional engineer shall supervise or direct the supervision of construction in accordance with the construction quality assurance plan.
   4. 4. The owner or operator’s qualified professional engineer shall submit summary reports of construction activities and test results according to a schedule approved by the Department.
   5. 5. The owner or operator shall immediately report to the Department any condition encountered during construction that requires a deviation from the approved plans and specifications.
   6. 6. The owner or operator shall promptly submit a written request for approval of any necessary change with sufficient information to justify the proposed change. The owner or operator shall not commence construction without the written approval of the Director unless the change is a minor change. A minor change is a change that complies with the requirements of this Article and provides equal or better safety performance.
   7. 7. Upon completion of construction, the owner or operator shall notify the Department in writing. The Department shall make a final inspection. The owner or operator shall correct any deficiencies noted during the inspection. The owner shall not use the CCR surface impoundment before issuance of a permit or permit modification unless the Director issues written approval.

6. F. Completion Documents for a Significant or High Hazard Potential CCR Surface Impoundment. Within 90 days after completion of the construction or removal work for a significant or high hazard potential CCR surface impoundment and final inspection by the Department, the owner or operator shall file the following:

   1. 1. One set of full sized as constructed drawings prepared and sealed by the qualified professional engineer who supervised the construction. If changes were made during construction, the owner or operator shall file supplemental drawings showing the CCR surface impoundment and appurtenances as actually constructed.
   2. 2. Construction records, including grouting, materials testing, and locations and baseline readings for permanent bench marks and instrumentation, initial surveys, and readings.
   3. 3. Photographs of construction from exposure of the foundation to completion of construction.
   4. 4. A brief completion report summarizing the salient features of the project, including a description of the causes for any changes or deviations from the approved drawings and specifications that were made during the construction phase.
   5. 5. A schedule for filling the impoundment, specifying fill rates, CCR surface or liquid level elevations to be held for observation, and a schedule for inspecting and monitoring the CCR surface impoundment.

   6. 6. An operating manual for the CCR surface impoundment and its appurtenant structures. The operating manual shall include a process for safety inspections prescribed in R18-13-1004. The operating manual shall include schedules for surveillance activities and baseline information for any installed instrumentation as follows:

      1. a. The frequency of monitoring,
      2. b. The data recording format,
      3. c. A graphical presentation of data, and
      4. d. The person who will perform the work.

7. G. Construction Drawings, Construction Specifications, and Engineering Design Report for a High, Significant, or Low Hazard Potential CCR Surface Impoundment. The owner or operator and qualified professional engineer are responsible for complete and adequate design of a CCR surface impoundment and for including in the application all aspects of the design pertaining to the safety of the CCR surface impoundment.

   1. 1. Construction Drawing Requirements. The construction drawings required by subsections (B), (C), and (D) of this Section shall include the following:

      1. a. The seal and signature of a qualified professional engineer.
      2. b. One or more topographic maps of the CCR surface impoundment, spillway, outlet works, and reservoir on a scale large enough to accurately locate the CCR surface impoundment and appurtenances, indicate cut and fill lines, and show the property lines and ownership status of the land. Contour intervals shall be compatible with the height and size of the CCR surface impoundment and its appurtenances and shall show design and construction details.
      3. c. A reservoir area and capacity curve that reflect area in acres and capacity in acre-feet in relation to depth of CCR and liquids and elevation in the reservoir. The construction drawings shall show the spillway invert and top of CCR surface impoundment elevations. The construction drawings shall also show the reservoir volume and space functional allocations. The construction drawings may include alternate scales as required for the owner or operator’s use.
      4. d. Spillway and outlet works rating curves and tables at a scale or scales that allow determination of discharge rate in cubic feet per second at both low and high flows as measured by depth of water passing over the spillway control section.
      5. e. A location map showing the CCR surface impoundment footprint and all exploration drill holes, test pits, trenches, adits, borrow areas, and bench marks with elevations, reference points, and permanent ties. This map shall use the same vertical and horizontal control as the topographic map.
      6. f. Geologic information including 1 or more geologic maps, profile along the centerline, and other pertinent cross sections of the CCR surface impoundment site, spillway or spillways, and appurtenant structures, aggregate and material sources, and reservoir area at 1 or more scales compatible with the site and geologic complexity, showing logs of exploration drill holes, test pits, trenches, and adits.
      7. g. One or more plans of the CCR surface impoundment to delineate design and construction details.
      8. h. Foundation profile along the CCR surface impoundment embankment centerline at a true scale where the vertical scale is equal to the horizontal scale, showing the existing ground and proposed finished grade at cut and fill elevations, including anticipated geologic formations. The foundation profile shall include any proposed grout and drain holes.
      9. i. Profile and a sufficient number of cross sections of the CCR surface impoundment embankment to delineate design and construction details. The drawings shall illustrate and show dimensions of camber, details of the top, core zone, interior filters and drains, and other zone details. The profile of the CCR surface impoundment may be drawn to different horizontal and vertical scales if required for detail. A maximum section of the CCR surface impoundment shall be drawn to a true scale, where the vertical scale is equal to the horizontal scale. The outlet conduit may be shown on the maximum section if this is typical of the proposed construction.
      10. j. One or more CCR surface impoundment embankment foundation plans showing excavation grades and cut slopes with any proposed foundation preparation, grout and drain holes, and foundation dewatering requirements.
      11. k. Plan, profile, and details of the outlet works, including the intake structure, the gate system, conduit, trashrack, conduit filter diaphragm, conduit concrete encasement, and the downstream outlet structure. The drawings shall include all connection and structural design details.
      12. l. Plan, profile, control section, and cross sections of the spillway, including details of any foundation preparation, grouting, or concrete work that is planned. A complex control structure, a concrete chute, or an energy dissipating device for a terminal structure shall include both hydraulic and structural design details.
      13. m. Hydrologic data, drainage area and flood routing, and diversion criteria.

   2. 2. Construction Specification Requirements. The construction specifications required by subsections (B), (C) and (D) of this Section shall include the following:

      1. a. The seal and signature of a qualified professional engineer.
      2. b. The statement that the construction drawings and specifications shall not be materially changed without the prior written approval of the Director.
      3. c. A detailed description of the work to be performed and a statement of the requirements for the various types of materials and installation techniques that will enter into the permanent construction.
      4. d. The statement that construction shall not be considered complete until the Director has approved the construction in writing.
      5. e. The statement that the owner or operator’s qualified professional engineer shall control the quality of construction.

      6. f. The following construction information:

         1. i. All earth and rock material descriptions, placement criteria, and construction requirements for all elements of the CCR surface impoundment and related structures.
         2. ii. All concrete, grout, and shotcrete material and mix descriptions, placement and consolidation criteria, temperature controls, and construction requirements for all elements of the CCR surface impoundment and related structures.
         3. iii. Material criteria and material testing, cleaning, and treatment. If foundation or curtain grouting is required, the specifications shall describe the type of grout, grouting method, special equipment necessary, recording during grouting, and foundation monitoring to avoid disturbance from grouting.
         4. iv. All materials testing that will be performed by the contractor for pre-qualification of materials, including special performance testing, such as water pressure tests in conduits. The Director shall accept materials that are pre-tested successfully and constructed in-place in accordance with specifications.
         5. v. A plan for control or diversion of surface water during construction. The design qualified professional engineer may determine frequency of storm runoff to be controlled during construction, commensurate with the risk of economic loss during construction.
         6. vi. Criteria for blast monitoring and acceptable blast vibration levels, including particle velocities for the CCR surface impoundment and other critical appurtenances. Monitoring equipment and monitoring locations shall be specified.
         7. vii. Instrumentation material descriptions, placement criteria, and construction requirements and a statement that instrumentation shall be installed by experienced specialty subcontractors.

   3. 3. Engineering Design Report Requirements. The engineering design report required by subsections (B), (C) and (D) of this Section shall include the following:

      1. a. The seal and signature of a qualified professional engineer.
      2. b. The classification under 40 CFR 257.74(a)(2) of the proposed CCR surface impoundment, or for the proposed lateral expansion of an existing CCR surface impoundment.
      3. c. Hydrologic considerations, including calculations and a summary table of data used in determining the required emergency spillway capacity and freeboard, and design of any diversion or detention structures. The design report shall include input and output listings.
      4. d. Hydraulic characteristics, engineering data, and calculations used in determining the capacities of the outlet works and emergency spillway. The design report shall include input and output listings.
      5. e. Geotechnical investigation and testing of the CCR surface impoundment site and reservoir basin. Results and analysis of subsurface investigations, including logs of test borings and geologic cross sections.
      6. f. Guidelines and criteria for blasting to be used by the contractor in preparing the blasting plan.
      7. g. Details of the plan for control or diversion of surface water during construction.
      8. h. Details of the dewatering plan for subsurface water during construction.
      9. i. Testing results of earth and rock materials, including the location of test pits and the logs of these pits.
      10. j. Discussion and design of the foundation blanket grouting, grout curtain, and grout cap based on foundation stability and seepage considerations.
      11. k. Calculations and basic assumptions on loads and limiting stresses for reinforced concrete design. The design report shall include input and output listings.
      12. l. A discussion and stability analysis of the CCR surface impoundment embankment including appropriate seismic loading, safety factors, and embankment zone strength characteristics. Analyses shall include both short-term and long-term loading on upstream and downstream slopes. The design report shall include input and output listings.
      13. m. A discussion of seismicity of the project area and activity of faults in the vicinity. The design report shall use both deterministic and statistical methods and identify the appropriate seismic coefficient for use in analyses.
      14. n. Discussion and design of the cutoff trench based on seepage and other considerations.
      15. o. Permeability characteristics of foundation and CCR surface impoundment embankment materials, including calculations for seepage quantities through the CCR surface impoundment, the foundation, and anticipated in the internal drain system. The design report shall include input and output listings. The design report shall include copies of any flow nets used.
      16. p. Discussion and design of internal drainage based on seepage quantity calculations. The design report shall include instrumentation necessary to monitor the drainage system and filter design calculations for protection against piping of foundation and embankment.
      17. q. Erosion protection against waves and rainfall runoff for both the upstream and downstream slopes, as appropriate.
      18. r. Discussion and design of foundation treatment to compensate for geological weakness in the CCR surface impoundment foundation and abutment areas and in the spillway foundation area.
      19. s. Post-construction vertical and horizontal movement systems.
      20. t. Discussion of foundation conditions including the potential for subsidence, fissures, dispersive soils, collapsible soils, and sink holes.

8. H. This Section consists of enhancements to 40 CFR 257, subpart D based on Arizona dam safety standards and apply in addition to 40 CFR 257, subpart D but do not apply to:

   1. 1. CCR surface impoundments with a maximum height of less than 6 feet, regardless of storage capacity;
   2. 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. 3. CCR surface impoundments with a maximum height greater than 25 feet and a storage capacity of 15 acre-feet or less.

Historical Note

New Section made by final rulemaking at 31 A.A.R. 1363 (April 25, 2025), effective date June 1, 2025 (Supp. 25-2).