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Cleanup guidance

Listed below are topics for cleanup guidance information. Select the topic to see the listing of related documents.

This technical series provides an effective methodology to characterize DNAPL sites and to develop an appropriate strategy towards addressing DNAPL. The documents are technical in nature and are developed for use by experienced practitioners. Go to the DNAPL webpages.

Vapor intrusion best management practices

The MPCA has developed procedures for vapor intrusion mitigation and public communication work that will be used by MPCA and our contractors for doing these aspects of vapor intrusion work. The procedures and documents were developed working closely with the Minnesota Department of Health, environmental consultants under contract to MPCA and expert practitioners in radon mitigation.

Vapor intrusion guiding principles — Version 4.0

The vapor intrusion guiding principles are the basis for the more detailed direction and guidance outlined in the vapor intrusion BMP’s.

  • Underground chemical vapors can migrate from the source of contamination through the soil and  building foundations into indoor air creating a health concern.
  • The primary goal of vapor intrusion work is to identify and address potential human health risks.
  • Effective public communication is an essential aspect of vapor intrusion work. This includes public awareness of health risks from vapor intrusion, vapor intrusion areas of concern, areas where mitigation has been installed and areas where more testing is needed.
  • Building mitigation decisions are based on current and future possibilities of a health risk from vapor intrusion.
  • Multiple factors contribute to variations in soil vapor contaminant levels.
  • Seasonal sampling from multiple sampling points are needed to determine there is no vapor intrusion risk.
  • The effectiveness of a mitigation system needs to be verified with confirmation testing.
  • Expedited action is needed when the data indicates the potential for a short-term health risk.
  • A plan is needed to assure continued operation of mitigation systems until data shows continued operation is no longer needed.
  • Future property owners need to be notified of the presence and need for continued operation of mitigation systems or unresolved vapor intrusion risks. 
  • When there is a source creating vapor contamination, the best practice is to remediate the source if feasible.
  • The obligation for addressing the possibility of vapor intrusion into a building and the source of the contamination are different for Superfund responsible parties compared to non-responsible voluntary parties and property owners.
  • A clear and predictable process is important for timely facilitation of property transactions.

Investigation and building mitigation decision best management practices

PDF icon Vapor investigation and mitigation decision best management practices (c-rem3-06e)

Map templates

Building mitigation best management practices

PDF icon Vapor mitigation best management practices (c-rem3-06)

Parking facilities and vapor mitigation - new!

This document advances a comprehensive understanding of the design, construction, and operation of parking facilities as these topics relate to vapor intrusion and vapor intrusion mitigation. Of primary concern is subsurface soil vapor contaminated with non-petroleum and petroleum related VOCs that may enter a parking facility and subsequently into adjacent occupied space. This resource specific to parking facilities provides a summary of readily available literature, codes, parking facility products, experiences with parking facility forensic investigations, and discussions with design engineers.

PDF icon Parking facilities and vapor intrusion mitigation (c-rem3-06i)
 

Public communication best practices

Updated May 2021: Soil reference values (SRVs) are a screening tool used to evaluate potential human health risks from exposure to contaminated soil. They are derived using exposure assumptions based on specific land-use scenarios.

File Soil reference value (SRV) spreadsheet (c-r1-06)

This soil reference value spreadsheet contains two sets of generic SRVs by land use: Residential/recreational and commercial/industrial. For each land use category, click on the corresponding “Worksheet” tab to see the SRVs.

PDF icon Soil reference value (SRV) technical support document (c-r1-05)

Background information on how the SRVs were calculated, including the default exposure assumptions used for each land use category. The document also provides information on how to use the generic SRVs to evaluate potential risk from exposure to contaminated soil.

PDF icon Background threshold value (BTV) evaluation (c-r1-08)

The calculated generic SRVs for eight metals and two organic compounds were deemed less-than-typical background concentrations. This report presents the MPCA’s evaluation of selected data sets to determine a reasonable background threshold value to use in place of the calculated SRV. The ten compounds for which a background threshold value is used instead of an SRV are clearly identified in the SRV spreadsheet.

The Contaminated Groundwater Discharge general permit covers discharges of contaminated groundwater to surface water or land; the permit is required if the water is, or has the potential to be, contaminated. The permit addresses the most common causes of contaminated groundwater, including releases of petroleum, volatile organic compounds, and other hazardous substances.

Individual permits

Not all contaminated groundwater pumpout discharges are covered by the general permit. Some projects that could contribute to violations of water quality standards, involve agricultural chemicals, contain polychlorinated biphenyls, dioxins, or furans, or meet certain other criteria must have an individual permit. See the guidance below for more information. Individual permits will require additional processing time and higher application fees, and will be subject to a 30-day public notice period.

Permits must be obtained before any discharges occur.

How to apply

Complete and submit:

  • File Industrial Groundwater Pump Out Application (wq-wwprm7-29)
  • Microsoft Office document icon Water Quality Transmittal Form (wq-wwprm7-03) — Include the $1,240 application fee for general permit coverage. Fees for individual permits are calculated using the wastewater fee schedule.
  • Projects with Category II and III discharges must submit priority pollutant scan analysis of the proposed discharge as defined in 40 CFR, Part 423.
  • Site diagram showing the discharge path from pumpout, through treatment, and to the receiving water or land application. Discharges to municipal stormwater systems will need documented approval from the municipality.
  • When chemical additives will be used to treat contaminated water, additional information may be required — see the guidance document below.

Institutional controls — also known as land use restrictions, activity use limitations, and land use controls — are restrictions, conditions, or controls imposed on a property to protect cleanup work and minimize the potential for exposure to remaining contamination. Institutional controls typically work by limiting how the land or resources on it can be used, or by providing information that helps modify or guide behavior on the property.

Institutional controls can be implemented when property conditions or residual contamination does not allow for unrestricted land use. Institutional controls are not intended to be a sole remedy, but are typically part of a property’s overall remedy and protection work. The MPCA may require an institutional control as a condition of liability assurance for a property.

Common institutional controls

  • Environmental covenant and easement (previously called declarations of restrictions and covenants) — Required when a specific action or activity restriction is needed to protect human health or the environment. For example, the covenant might prohibit disturbing soil in a certain location or below a certain depth, or require operating a vapor mitigation system in a building on the property.
  • Affidavit concerning real property contaminated with hazardous substances — Required when no specific action or activity restriction is needed, but a notice of residual or potential contamination on the property is warranted.
  • Bond declaration — Required when state general obligation bonds have been used to improve a property, and the sale or use of the property is then restricted based on state and federal law.

Institutional control documents are typically recorded at either the county recorder’s or registrar of titles office, after cleanup is completed or the bonds have been spent. Templates for the covenant and affidavit:

A list of MPCA Remediation Division sites with institutional controls is available on the agency's Minnesota Geospatial Commons page. The data is refreshed daily and can be downloaded and then sorted. If you have a question about a particular institutional control or find an error in the data, please contact us at instcontrols.pca@state.mn.us.

Soil leaching value (SLV) guidance

The SLV guidance document and the spreadsheet containing SLVs are new guidance from the MPCA Remediation Division for evaluating risks posed by leaching of contaminants in soil to groundwater.

Corrective action design (CAD) for use at Superfund, Resource Conservation and Recovery Act, and VIC Programs

Effective July 1, 2011, the CAD guidance developed earlier by the Petroleum Remediation Program will be utilized at remediation sites, as set forth in the following policy document:

Other topics

General guidance

Release reporting

Soil excavation and treatment

Site investigation and risk evaluation

Corrective action

The MPCA has developed the following policy and guidance for the offsite reuse of excess soil or fill material for brownfield redevelopment sites. For unregulated fill material, please refer to:

For fill material with contaminant levels greater than the MPCA's most conservative risk-based standards, please refer to the following documents that detail procedures for brownfield redevelopment sites (that are enrolled in the MPCA's Voluntary Investigation and Cleanup (VIC) and/or Petroleum Brownfields (PB) programs) to move regulated fill from one VIC/PB site to another VIC/PB site, subject to the terms and conditions as outlined:

Effective June 2011, analytical methodology for the vast majority of remediation sites will be the short list of seven cPAHs. However, under certain site conditions the extended list of 25 cPAH compounds will be recommended. The policy document provides background and situations where the extended list of 25 cPAH methodology applies.

The MPCA will consider, on a case by case basis, disposal in appropriate Minnesota landfills of soils contaminated by mercury at concentrations which are both no greater than 4 ppm and non-hazardous. This will apply to soils from remediation and redevelopment sites. Any such disposal must occur in accordance with industrial solid waste management plans. For further discussion of this issue, please see the program management decision document below: