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WPD | Solid Waste - PCS Special Waste

Solid Waste Section | Special Waste

Petroleum Contaminated Soil

Revised On: Jan. 23, 2023 - 1:00 p.m.

What is Petroleum Contaminated Soil?

Petroleum Contaminated Soil (PCS) is soil excavated for storage, treatment or disposal containing any of the following contaminants at or above non-residential soil remediation levels (SRLs):1

benzene, toluene, ethylbenzene, total xylenes, acenaphthylene, anthracene, benz(A)anthracene, benzo(A)pyrene, benzo(B)fluoranthene, benzo(K)fluoranthene, chrysene, dibenz(A,H)anthracene, fluoranthene, fluorene, indenopyrene, naphthalene or pyrene.

Solid Waste PCS is excavated soil contaminated with petroleum, with regulated contaminates detected above residential SRLs but below non-residential SRLs.2

Waste Soil is soil where the regulated contaminants fall below residential SRLs but full remediation has not been completed.

If special waste results are above non-residential SRLs, verify the waste will not need to be classified as hazardous waste.

Petroleum Contaminated Soil Fact Sheet | View/Download >

Petroleum Contaminated Soil Waste Determination

A generator of excavated soil contaminated with petroleum is required to:

  • Determine whether the soil is PCS, solid waste PCS or waste soil.
  • Keep records of the determination for at least three years and make them available upon ADEQ request
  • Make the determination using one of the following methods:3
    1. Testing the soil. Use an Arizona Department of Health Services licensed laboratory and approved testing methods, EPA SW-846, for the analysis of the samples.
    2. Using generator knowledge of the characteristics of the contaminated soil, if the source of the contamination is known. ADEQ may require confirmation sampling to confirm accuracy.
  • Perform sampling of contaminated soils in accordance with a site-specific written sampling plan, approved by ADEQ, that is consistent with requirements of one of the following:
    1. “Test Methods for Evaluation Solid Waste”, EPA SW-846, 3rd Edition Volume II: Field Manual, Physical/Chemical Methods, Chapter Nine.
    2. “Quality Assurance Project Plan”, Chapter 9, May 1991 Edition, Arizona Department of Environmental Quality, Phoenix, Arizona.

Note that other requirements may apply.4

Sampling Fact Sheet | View/Download >

What to Do for Petroleum Contaminated Soil:

PCS should only be transported by an ADEQ-approved special waste transporter to an ADEQ-approved special waste receiving facility. The special waste transporter must make sure the PCS is in closed containers and that the vehicle used for transports is constructed to prevent leaks and spills and is covered to prevent blowing of material.5

A facility that received PCS for treatment, storage or disposal is required to meet one of the following general design criteria:6

  • Hold PCS in a containment system designed to stop the flow of contaminants into subsurface soil, groundwater, or surface water. The containment system is required to meet the following criteria:
    1. Maintain a maximum hydraulic conductivity of no more that 1x10-7 cm/sec
    2. Be designed to provide structural integrity throughout the life of the facility
  • An alternative designed is required to contain, at minimum, all of the following and demonstrate that the design will limit discharges to the maximum extent practicable:
    1. The hydrogeological setting of the facility and the capacity of the liner and soils to prevent discharge to groundwater or surface water
    2. The operating methods, processes, or other alternatives to be used at the facility
    3. Additional factors which would influence the quality and mobility of the leachate produced and the potential for that leachate to migrate to groundwater or surface water.
  • Design to prevent run-on and run-off. The design is required to provide run-on control for peak discharge from a 24-hour, 25-year storm even. Run-off is required to be controlled and collected for at least the water volume resulting from a 24-hour, 25-year storm event.
  • Restrict the flow of the 100-year floodplain, reduce temporary water storage capacity of the floodplain, or be maintained in a manner which results in washout or inundation of the PCS.
  • Control public access and prevent unauthorized vehicular traffic and illegal dumping
  • Manage standing water that has come into contact with the PCS

A PCS storage facility7 cannot store a shipment of PCS for a period exceeding one year form the date of the shipment. Each shipment is required to be identified by where it came from, and is stored separately from other shipment to reduce contamination and commingling until all sampling results have been received. PCS should be stored within an approved containment system and not commingled with treated soils. A PCS storage area, tank, or container used for storage is required to have the following markings:

  • CAUTION:  CONTAINS PETROLEUM-CONTAMINATED SOIL
  • GENERATOR NAME:
  • GENERATIOR SPECIAL WASTE ID:
  • ACCUMULATION START DATE:

The storage facility will fill in the accumulation start date at the time the PCS is placed into storage. The labels should be legible, not obstructed from view, on a high contrast background, and sufficiently durable to equipment or exceed the duration of the storage. Letter in size should be 1 inch and in Sans Serif, Gothic, or Block style.

Tanks or containers used for storage must meet the following requirements:

  • Prevent leakage of the PCS and any free liquids from the tank or container;
  • Be made of, or lined with, materials which will not react with the PCS;
  • Be kept closed during storage except to add or remove PCS;
  • Not be opened , handled, or stored in a manner which may rupture the tank or container or cause a leak;
  • Inspected monthly by the owner or operator of the facility for leaks and deterioration. A written record of the inspection is required to be prepared at the time of inspection and document any corrective action, if any, that was taken as a result of the inspection.

A PCS storage facility, which PCS is stored in piles, is required to comply with the following:

  • Cover all storage piles or otherwise manage to control wind dispersal of PCS
  • Storage piles of PCS are required to be inspected weekly and a written record of the inspection be prepared at the time of the inspection which documents any corrective action as a result of the inspection and include the following:
    1. Deterioration, malfunctions, or improper operation of run-on and run-off control systems
    2. Malfunction of wind dispersal control systems
    3. Presents of leachate in and the malfunction of any leachate collection and removal systems

PCS from one or more points under the control of a single generator may be accumulated on a site under the control of that generator for up to 90 days before a shipment to a storage, disposal, or treatment facility is made.
An accumulation site must comply with all of the following:8

  • Each shipment is required to be identified by where it came from, and is stored separately from other shipment to reduce contamination and commingling until all sampling results have been received. PCS should be stored within an approved containment system and not commingled with treated soils.
  • A PCS accumulation area, tank, or container used for storage is required to have the following markings:
    1. CAUTION:  CONTAINS PETROLEUM-CONTAMINATEDSOIL
    2. GENERATOR NAME:
    3. GENERATIOR SPECIAL WASTE ID:
    4. ACCUMULATION START DATE:
  • Fill in the accumulation start date at the time the PCS is placed into storage. The labels should be legible, not obstructed from view, on a high contrast background, and sufficiently durable to equipment or exceed the duration of the storage. Letter in size should be 1 inch and in Sans Serif, Gothic, or Block style.
  • Tanks or containers used for storage must meet the following requirements:
    1. Prevent leakage of the PCS and any free liquids from the tank or container;
    2. Be made of, or lined with, materials which will not react with the PCS;
    3. Be kept closed during storage except to add or remove PCS;
    4. Not be opened , handled, or stored in a manner which may rupture the tank or container or cause a leak;
    5. Inspected monthly by the owner or operator of the facility for leaks and deterioration. A written record of the inspection is required to be prepared at the time of inspection and document any corrective action, if any, that was taken as a result of the inspection.

PCS stored in piles are required to comply with the following:

  • Cover all storage piles or otherwise manage to control wind dispersal of PCS
  • Storage piles of PCS are required to be inspected weekly and a written record of the inspection be prepared at the time of the inspection which documents any corrective action as a result of the inspection and include the following:
    1. Deterioration, malfunctions, or improper operation of run-on and run-off control systems;
    2. Malfunction of wind dispersal control systems;
    3. Presents of leachate in and the malfunction of any leachate collection and removal systems
  • While PCS is at an accumulation site the owner or operator must control public access and prevent unauthorized vehicular traffic and illegal dumping.
  • Manage PCS to prevent it from being exposed to storm water run-on and run-off.

PCS must be disposed of at an ADEQ-approved special waste receiving facility or hazardous waste management facility.9

Keep all PCS records for at least 3 years. If you are notified of an enforcement action by ADEQ, records are required to be kept until a final determination has been made in the matter or in accordance with the final determination.10


1A.R.S. § 49-851(3)
2A.A.C. R18-13-1601(13)
3A.A.C. R18-13-1604(A)
4A.A.C. R18-13-1604(C-D)
5A.A.C. R18-13-1605
6A.A.C. R18-13-1608
7A.A.C. R18-13-1611
8A.A.C. R18-13-1612
9A.A.C. R18-13-1613
10A.A.C. R18-13-1614