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WPD | Solid Waste - Landfills

Solid Waste Section

Landfills

Revised On: Jan. 29, 2024 - 12:00 p.m.

The following types of facilities are subject to Solid Waste Facility Plan approval or Aquifer Protection Permit (APP) requirements:

Municipal Solid Waste Landfills (MSWLFs)

A MSWLF is any solid waste landfill that accepts household waste, household hazardous waste or conditionally exempt small quantity generator waste. MSWLFs are required to obtain Solid Waste Facility Plan (SWFP) approval.1 The owner/operator of a solid waste facility with an approved Solid Waste Facility Plan is required to notify ADEQ of any change to the facility, and ADEQ determines the type of change, which have certain requirements:2

Type I

A Type I change is an insignificant modification that does not require notification to ADEQ. These changes do not need ADEQ approval, a fee payment or a public notice. This includes changes to a facility that are not directly related to the replacement of equipment or structures with similar items. Examples include cosmetic changes at a landfill, purchasing a new pickup truck or changing accountants.

Type II

A Type II change is a minor modification that requires notification to ADEQ. This includes changes to a facility that are directly related to the physical management of solid waste that do not require detailed review by ADEQ. Examples include minor changes in construction or operations from the approved Solid Waste Facility Plan. While notifying ADEQ is required, ADEQ's approval is not, and there are no payment fees or public notices required.

Type III

A Type III change is a substantial change that does not require public notice. This includes changes that are significant, that require detailed review by ADEQ and that are equally or more protective of the public health and environment. Notifying ADEQ, ADEQ director approval, and a Solid Waste Facility Plan Review are required before implementation. Examples include:

  • An annual update approval of a financial assurance mechanism
  • A change to a facility required by a change to a statute or rule
  • A change to the existing approved design settings or standards that does not increase approved facility capacity, or add or remove pollution control devices
  • An addition to the types of waste approved to be handled at the facility
  • An addition to the types of alternative daily cover approved for use at the facility
  • A change to the approved monitoring program for a facility, including the addition or deletion of a monitoring point or a monitoring constituent, or a change in the frequency of groundwater monitoring
  • Any modification to the storm water run-on and run-off control system for the facility
  • A change to the landfill gas monitoring frequency
  • An addition of a closure plan or closure components to an approved facility plan, and any corresponding change to the facility's financial assurance plan
  • A change to the approved closure plan or approved closure components
  • A change to the approved post-closure care or maintenance program, including a reduction in the post-closure care period
  • A change to the post-closure use of the facility site
  • A change of financial assurance mechanism
  • A change in the total storage, process, treatment, or disposal capacity approved for the solid waste facility, to be achieved through greater compaction of solid waste
  • Significant corrective action plan changes
  • Change in landfill ownership

Type IV

A Type IV change is a substantial change that requires public notice. This includes significant changes in the total storage, process, treatment or disposal capacity of the solid waste facility. Before implementation, the director must approve a Type IV change to the design or operation of an approved Solid Waste Facility Plan. Examples include:

  • A change in the total storage, process, treatment or disposal design capacity approved for the solid waste facility, to be achieved by means other than greater compaction of the solid waste
  • For a facility that is a municipal solid waste landfill or a solid waste land disposal facility, a change that is described by any of the following:
    • A vertical or lateral expansion
    • A side slope increase or decrease
    • A change to an approved base liner system
  • A change to the leachate collection, recovery and disposal system

Common violations and how to prevent them | View Compliance Assistance Page >

Non-Municipal Solid Waste Landfills (non-MSWLF)

Non-MSWLFs include facilities commonly known as construction and demolition debris (C&D) landfills as well as private landfills. C&D landfills typically accept solid waste derived from constructing, repairing or remodeling of buildings or other structures or demolishing buildings or other structures. Private landfills accept only permitted wastes generated onsite. These facilities are subject to APP requirements and federal requirements.3

Non-MSWLF at Mining Operations — General Permit

An owner/operator of a non-MSWLF at mining operations may file a Notice of Intent to Operate under the General Permit4 and obtain a written Authorization to Operate (ATO) from the ADEQ. In addition, the landfill must be identified as a discharging unit in an area-wide APP in order to operate under the General Permit.

Municipal Solid Waste Surface Impoundments

Municipal solid waste surface impoundments, such as leachate collection ponds, are subject to APP requirements. The Solid Waste Unit receives and reviews the APP application for these types of facilities. MSWLF owners/operators are required to notify ADEQ of any change to the facility.


1The Arizona Revised Statutes (ARS) adopt the federal criteria for MSWLFs — 40 Code of Federal Regulations (CFR) 258 or "Resource Conservation and Recovery Act (RCRA) Subtitle D" — by reference.
2Per ARS § 49-762.06
3Of 40 CFR Part 257
4Arizona Administrative Code (AAC) R18-13-802