TREATMENT AND DISPOSAL OF PETROLEUM CONTAMINATED SOIL   (June 1996)   
Revised May 1998    

1.1 Scope

2.0 ASSOCIATED REGULATIONS AND GUIDELINES

3.0 CLASSIFICATION AND HANDLING OF PCS

3.1 Classification

3.2 Characterization of the Soil Shipment

4.0 TRANSPORTATION OF PCS

 5.0 PERMITTING AND LICENSING PROCEDURES

5.1 Municipal Waste Disposal Grounds

5.2 Commercial PCS Facilities

5.3 Single Use Sites

5.4 Minimum Application Information

6.0 DESIGN AND OPERATIONS AT PCS TREATMENT

AND DISPOSAL SITES

6.1 Baseline Information and Inspections

6.2 Design Considerations

6.3 Operating Considerations

6.4 Confirmatory Testing of Treated Soil at PCS Treatment Site

6.5 Record Keeping and Reporting

 
7.0 REMOVAL AND RE-USE OF TREATED SOIL

 8.0 DECOMMISSIONING OF PCS TREATMENT FACILITY 11

Additional information - Manitoba Criteria for Soil

Manitoba Environment regional offices list

This document on the treatment and disposal of petroleum contaminated soil (PCS), has been developed to assist environmental consultants, petroleum service contractors, waste disposal ground operators, and petroleum storage tank owners in the management of petroleum contaminated soil. Leaking petroleum storage tanks and petroleum contaminated sites can have serious environmental and public safety implications. Contaminated soil removed from petroleum storage tank sites requires proper treatment and/or disposal to ensure it does not pose a safety, public health, or environmental threat.

The following sections of this document discuss procedures that may be used to meet these objectives. Many people play a role in the management of petroleum contaminated soils, and by reading this document you will have a better understanding of how to properly dispose of and/or treat petroleum contaminated soil.

1.1 Scope

The scope of this document refers to soil contaminated with residual concentrations of refined petroleum products such as gasoline, diesel fuel, aviation fuel, fuel oil, waste oil, and related petroleum products stored in petroleum storage tanks. This document does not supersede existing regulations or policies governing the classification, handling, disposal or treatment of petroleum contaminated soils and is intended to serve as an aid to parties involved in the design and operation of soil treatment facilities.

This document outlines the requirements and operating procedures for the disposal/treatment of PCS at licensed soil treatment facilities, Manitoba Waste Disposal Grounds (WDG), and at single-use soil treatment sites approved by Manitoba Environment.

The principle treatment method for PCS at these types of sites is by landfarming. Under normal circumstances, the operating philosophy of the soil treatment facility should, to the maximum extent possible, control excessive emission of volatile organic compounds (VOC) to the atmosphere. In addition, losses of petroleum compounds by leaching, should be controlled.

Alternative methods of soil remediation at approved PCS treatment sites, such as enhanced bioremediation, asphalt incorporation, soil washing, thermal treatment, etc., may be considered, where applicable.

Manitoba Environment has developed objective guidelines with recommended clean-up criteria for the remediation of sites contaminated with petroleum hydrocarbon compounds. Manitoba's remediation guidelines recommend that the nature and extent of subsurface contamination be delineated prior to the implementation of remedial activities. This information will assist in determining the type(s) and range of concentrations of petroleum hydrocarbon compounds in the contaminated soil, and the amount of contaminated soil requiring treatment or disposal.

Other existing Manitoba Environment Guidelines pertinent to PCS are as follows:

It is important that petroleum storage tank owners, or contractors working for the tank owner, develop a handling plan prior to disposal of PCS. This management plan should cover the handling of the PCS from cradle to grave, and include procedures necessary for compliance with all provincial regulations and local policies. (see Information Bulletin 96-02E)

3.1 Classification

Prior to developing a procedure for handling PCS to be removed from a site, it is necessary to classify the soil based on the specific petroleum product type in question, and the degree of severity of hydrocarbon contamination. The subsequent handling, treatment and/or disposal of contaminated soil are dependent on the classification. Classification is based on results of analytical laboratory testing for petroleum hydrocarbon compounds and should be conducted prior to excavation of the soil.

Petroleum contaminant concentrations should be determined in reference to the Canadian Council of Ministers of the Environment Recommended Candadian Soil Quality Guidelines.

3.2 Characterization of the Soil Shipment;

Detailed characterization of PCS, specifically contaminant types and concentrations, soil types and estimated volumes, must be conducted prior to any soil being shipped to a soil treatment/disposal facility. Procedures for characterization of the soil should follow those outlined in the Manitoba Environment Guideline.

PCS is not considered hazardous waste unless the soil is contaminated with Polychlorinated Biphenyls or meets the primary classification for classes 2 to 6 and 8 under The Dangerous Goods Handling and Transportation Act and regulation thereunder. PCS generators who wish to transport hazarous waste class PCS must ensure that they are registered with Manitoba Environment and that the shipments are manifested and transported by a licensed carrier pursuant to MR 175/85.

Trucks containing the PCS should be equipped with tarpaulins to reduce wind blown particles and volatilization of petroleum constituents. During PCS transport, trucks must also effectively contain all residual liquids generated from the soil.

The procedure for obtaining authorization to establish and operate a facility for the treatment of contaminated soils will depend on the type of facility being proposed. The various approval processes are described in this section. Regardless of the type of facility, it is anticipated that the design and operating parameters will generally follow the provisions in this guideline.

5.1 Municipal Waste Disposal Grounds

Soils which contain petroleum contamination at a concentration below Manitoba Level III criteria can be received at a landfill and used directly as cover material without requiring further treatment. The landfill must be in compliance with Manitoba Regulation 150/91 under the Manitoba Environment Act. Written authorization from the appropriate regional office of Manitoba Environment and the landfill owner must be obtained for each originating site before this disposal option is used.

Where a designated soil treatment facility is to be developed as part of a waste disposal ground site, the authorization for the PCS facility will be issued as a variance to the operating permit for the waste disposal ground issued pursuant to Manitoba Regulation 150/91. The application for the variance must contain adequate details to show that the proposed facility will meet the standards of this guideline. The application would be submitted to the appropriate Regional Director of the Operations Division of Manitoba Environment. The variance, if approved, would normally only apply to non-hazardous waste level soils. Acceptance of hazardous waste level soils would be considered on a site specific basis.

5.2 Commercial PCS Facilities

Proposals for soil treatment facilities which are not located at a municipal waste disposal ground, and which will be receiving soil from more than one originating site, will be processed through Manitoba Environment's regular licensing system. Facilities which will not be receiving hazardous waste level soil will be considered for licensing under The Environment Act. Facilities which intend to receive hazardous waste level soils will require a licence issued under The Dangerous Goods Handling & Transportation Act.

In either case, the application must be submitted to Larry Strachan, Director of Environmental Approvals at the Winnipeg office address shown on page 12.

5.3 Single Use Sites

Where existing commercial facilities are not available in the vicinity of a remediation project, consideration will be given to authorizing the establishment of a single use site. If approved, the site would only be used once for soils originating from one location. Single use sites must be decommissioned once treatment of the soil is completed to a satisfactory level.

Requests for authority to establish a single use treatment site shall be submitted to the appropriate Regional Director for Environmental Operations. Operation of the single use site shall not commence until written authorization has been received from the Director. No PCS classified as hazardous waste shall be received at a single use treatment site.

5.4 Minimum Application Information

Prior to developing a facility within the scope of this guideline, the proponent must provide Manitoba Environment with enough information to allow the department to assess whether the facility should be permitted. Larger, more complex facilities, will require a greater degree of detail in the proposal. As a general guide for all levels of facilities*, the following minimum information should be included in all applications:

* NOTE: The Regional Director may waive the requirement to submit portions of the information listed above for submissions for single use sites.

The information provided in this section describes, in a general sense, the typical minimum requirements for the design and operation of PCS treatment sites. More detailed information based upon the site specific conditions at a potential PCS treatment sites can also be provided in technical proposals which form part of approval submissions (see Section 5.0).

6.1 Baseline Information and Inspections

Geological and Hydrogeological Baseline Information

Prior to operation of a treatment/disposal facility, subsurface baseline information should be obtained on geological and groundwater conditions, to serve as the basis for future comparisons.

If soil treatment facilities are within the limits of Class I and Class II Manitoba WDG's, data from the existing test holes and groundwater monitoring systems may be used to establish baseline geological and groundwater conditions. The design of a groundwater monitoring system and monitoring requirements should be consistent with, and should include appropriate analytical testing parameters for PCS.

Where appropriate, soil textural analyses (i.e. grain size distribution, soil classification) and in-situ, or laboratory soil permeability testing should be conducted. Soil sampling for such analyses should be conducted at representative depth intervals.

Routine inspections should be conducted to confirm that operation of the treatment facility has not adversely affected local groundwater quality. Such inspections should, as a minimum, be conducted on an annual basis. Groundwater monitoring parameters should follow the baseline parameters outlined in the previous subsection.

An area used for treatment of PCS should be identified as a "designated area" which is used exclusively for this purpose. Such areas/facilities should be clearly marked to prevent unauthorized access onto the treatment area and possible disturbance or compaction. Physical barriers are also recommended to restrict unauthorized access.

Permanent visible markers (posts, pegs, etc.) should be installed at regular intervals of 5 m to 10 m along 2 perpendicular edges of the treatment area to serve as a reference grid for routine inspections and monitoring.

Location

Treatment cells should be located in areas where the underlying native soils consist of relatively low permeability deposits. Where this is not practical, the subgrade soil should be suitably prepared in order to provide a low permeability barrier to minimize vertical migration of leached petroleum contaminant compounds.

Siting of treatment cells in local depressions or on sloping ground with gradients of 5% or greater should be avoided.

Treatment cells should normally be located in areas where the local groundwater table is at least 3.0 m below the prepared base so as to minimize the possibility of groundwater contamination, to avoid saturation of the treatment layer due to groundwater fluctuations or capillary action, and to minimize susceptibility of the prepared base to frost action.

Soils impacted with petroleum hydrocarbons with benzene, toluene, ethylbenzene and xylene (BETX), where any of these individual constituents exceed 100 ppm (high impacted soils), shall be managed separately from other contaminated soils in a dedicated cell for treatment at Municipal Waste Disposal Grounds and Commercial PCS Facilities. The location of this cell shall be provided to the appropriate Manitoba Environment regional office.

Site Preparation

Treatment cells should be surrounded by berms to prevent surface water runoff and run-on. The berms should be designed to permit equipment access and have a minimum height of 0.5 m. Temporary cross-berms or windrows may also be provided to avoid mixing and cross-contamination of different soil shipments.

The base of treatment cells should be lined to prevent downward migration of contaminants below the treatment layer. The liner may consist of synthetic material, compacted clay, or a combination of both. Synthetic liners should be resistant to deterioration by sunlight and by petroleum hydrocarbon compounds, and should be installed to avoid puncture or tearing from soil spreading and tilling operations. Unless determined otherwise based on site-specific conditions, clay liners should normally have a minimum compacted thicknesses of 500 mm.

The base of the treatment area should be graded to facilitate surface drainage. A gradient of 1% to 2% will normally be adequate for this purpose. The impermeable layer on the base of the cell should be covered with a sacrificial indicator layer of sand, gravel or straw to ensure that the base is not penetrated during tilling or soil removal operations.

Design of treatment cells should include provisions to contain internal storm runoff and seepage in order to prevent offsite losses, and inundation of the treatment layer. Sumps or internal drainage ditches installed for this purpose should be suitably lined. Internal and external surface drainage systems must be capable of accommodating runoff volumes resulting from a 24-hour, 10 year frequency storm.

Monitoring Wells

The installation of monitoring wells must be incorporated in the design of the treatment area. In general, monitoring wells should be designed in order to monitor any groundwater contamination within the regional aquifer and within any perched groundwater-bearing soil formations beneath the site. The total number, location, and completion design of the monitoring wells must be approved by Manitoba Environment, prior to installation.

Operation of soil treatment facilities should incorporate inventory control and management procedures that account for the status and progress of the various individual soil shipments being treated concurrently. Information for contaminated soil for each originating site should include, but not necessarily be limited to, the following:

PCS placed in the treatment area should be spread in an even layer in a manner that avoids compaction and inter-mixing of different soil shipments.

The final thickness of the treatment layer normally should not exceed 300 mm or the effective mixing depth of on-site equipment (discs, roto-tillers, etc.), whichever is less.

Boulders and other large debris should be removed from the treatment layer to avoid potential damage to the tilling/aeration equipment, and to provide for optimum soil tillage.

Alternatively, soil may be placed in windrows which should normally not exceed 1 m in height. The windrows will require periodic mixing in a similar fashion to a treatment layer as described in the following section.

Layer Amendments

The treatment layer should be thoroughly aerated (mixed/tilled) on a regular basis. In most cases, a tillage frequency of 1 to 2 weeks should provide optimum soil aeration while minimizing excessive VOC emissions. In cases where enhanced soil remediation operations are being conducted, soil tilling frequency can be modified to suit the requirements of the remediation methods employed.

Soil augmentation procedures such as addition of fertilizers, desiccants, and soil bulking agents, are to be conducted only as approved within the licence or permit for the facility.

Periodic irrigation of the treatment layer may be necessary to avoid desiccation or prevent excessive wind blown dust. However, saturation of the soil should be avoided. Water impounded in runoff/leachate sumps may and should be used for treatment layer irrigation.

The use of sewage effluent or sewage sludge as an amendment is not recommended as it can introduce other contaminants into the soil.

Control/Discharge of Impounded Water

The soil treatment site must be capable of preventing run-on and run-off water from contacting contaminated soil. In addition, run-off water from the PCS treatment facility must be controlled on-site in order to prevent migration of contaminants. Surface water control will generally involve use of ditches, sumps, and culverts, along with a properly graded land surface.

Prior to any discharge or removal of impounded surface water from the PCS treatment facility, representative analytical testing of the water for petroleum hydrocarbon compounds must be conducted and the results reviewed by Manitoba Environment.

Air Monitoring

Where high impacted soils are being managed, air monitoring shall be conducted to ensure the following concentration limits are not exceeded at the property boundaries:
 

Air Contaminant	Period of Time Air Contaminant is Measured	Concentration Limit
Total Hydrocarbons	24-hour average	32 mg/m3
Benzene	24-hour average	150 µg/m3
Toluene	24-hour average	2000 µg/m3
Ethylbenzene	24-hour average	4000 µg/m3
Xylenes	24-hour average	2300 µg/m3

Air sampling shall be undertaken in adherence to accepted protocols and conducted during the period from April to November. The 24-hour average should commence during periods where volatilization will be at the maximum (i.e. soil placement and tilling). Air monitoring reports shall be provided to Manitoba Environment within 30 days of the sampling event.

6.4 Confirmatory Testing of Treated Soil at PCS Treatment Site

Confirmatory laboratory testing should be conducted on representative samples from the treatment layer in order to demonstrate that the accepted clean-up criteria have been achieved prior to re-use of the soil, as defined in Section 7.0 of this document.

Testing Protocol

The timing and methodology for confirmatory soil testing may be based on preliminary field hydrocarbon vapour testing of soil samples.

Soil vapour concentration measurements can be used as an indicator of the relative level of volatile hydrocarbons remaining in the soil. Using this technique field screening technique, the more highly contaminated areas of the treatment layer ("hot spots") can be identified. Once soil vapour concentrations have been lowered to near background levels in these areas, soil samples may be obtained for confirmatory laboratory analyses to prove that the appropriate clean-up criteria have been achieved.

Soil vapour concentrations within the treatment layer should be carried out according to Appendix A of the Manitoba Environment Guideline. Such measurements should be conducted on a regular grid pattern. A grid spacing of 5 m will ensure detection of "hot spots" equivalent to 10 m3 (one truck-load spread 300 mm thick) with an 80% confidence level.

Soil vapour surveys should not be conducted under saturated soil conditions.

Confirmatory laboratory analyses are to be conducted at the end of the remediation period to determine if acceptance criteria have been achieved.

Individual soil samples are usually combined to form one or more "composite" sample for the purpose of laboratory analyses. As a guideline, soil sampling should be conducted for every 20 m3 of PCS in order to generate a single composite sample for confirmatory laboratory analyses. For example, for a total volume of 100 m3 of treated PCS, a single composite sample should contain soil obtained from five locations within the contaminated soil mass.

The recommended number of composite soil samples to be submitted for confirmatory laboratory analyses is dependent upon the volume of the treatment layer as follows: