Key Conclusion:  The Low Threat Closure Policy (LTCP) can be used to obtain case closure for sites with residual contamination.  Most of these sites will require a Site Management Plan as part of a Deed Restriction that describes limitations and additional requirements for future redevelopment.

In August 2012 the California Regional Water Quality Control Board instituted the Low Threat Closure Policy (LTCP) in order to expedite the environmental case closure of leak cases based on a case-by-case analysis of risk to human health and safety and the environment. 

LTCP case closures are often subject to long-term management of residual contamination by recording a deed restriction (aka land use covenant or environmental lien).  The deed restrictions often require a Site Management Plan (SMP) to be implicated as a condition of the case closure.  Additional investigation, remediation or mitigation is required if the site will be redeveloped and/or the use is changed.

The LTCP requires the contamination site to meet several criteria (conditions) including the following:

  1. The unauthorized release is within the service area of a public water system
  2. The leak has been stopped and ongoing sources including free product, have been removed or remediated,
  3. the site has been adequately characterized, 
  4. The dissolved plume is not migrating,
  5. No water wells, deeper drinking water aquifers, surface water, or other sensitive receptors are likely to be impacted. 
  6. the site presents no significant risk to human health or the environment. 

Note that for volatile chemicals such as solvents, the threat to indoor air must also be addressed.

Key Conclusions: Low Threat Case Closure can allow for sales and re-financing of real property. However, the owner must recognize the implications of the closure on future operations and uses.

ERAS has made efficient and effective use of the California regulations that allow for proper low threat case closure of contaminated sites.

Note these closures are granted by regulatory agencies with contamination remaining in the subsurface. These case closures require the preparation of a Site Management Plan (SMP, sometimes called Risk Management Plans) and the recording of a Deed Restriction.

SMP – This is a document that shows the extent and location of remaining contamination and is an operations manual that describes steps to protect occupants and workers at the Property.

The SMP is specific to the site and to the medium that is the environmental issue (soil, groundwater, and vapor). Activities that may be regulated are activities such as the following.

  • construction activities such as installation of utility lines where workers could be exposed
  • changes in commercial use
  • installation of equipment or tenant improvements that could affect the foundation that would cause occupants to be exposed
  • construction of new buildings, re-paving or other redevelopment

Deed Restriction – the environmental agency granting case closure will require the recording of a deed restriction for the Property. The deed restriction will reference and include the SMP and will generally restrict the future uses of the Property to non-sensitive commercial uses.

The Property will be restricted from uses including but not limited to, hospitals, schools, children’s day care, and elderly care facilities and residential.
Any changes of use will require possible additional investigation, remediation and/or mitigation of the residual contamination. Note it is possible to use Property for almost any purpose if enough money is spent on remediation and/or mitigation.

Key Conclusion: ERAS has been using low threat case closure procedures to close leak cases. A solvent leak case in Sunnyvale has been approved for low threat solvent case closure after remediation, groundwater monitoring and risk assessment by ERAS. Other sites currently being closed by ERAS using low threat solvent case closure are in Richmond, Oakland and Milpitas. These closures will allow for bank financing of these additional properties.

The Regional Water Quality Control Board (RWQCB) has implemented this policy (Low Threat Solvent Case Closure) to close leak sites that do not pose a risk human health and safety and the environment. The low threat closure involves closing the site before beneficial uses of groundwater are fully restored. This action only makes sense if a conclusion is reached that cleanup standards can be met under natural conditions within a reasonable timeframe, following completion of cleanup and monitoring. In that sense, it can be thought of as a next step following either additional cleanup or groundwater monitoring.

The low threat solvent case closure being completed by ERAS on Wolfe Road in Sunnyvale will require proper abandonment of twelve groundwater monitoring wells on-site and off-site. In addition, the case closure, for this and other sites, require the following documents to be filed.

  1. Deed Restriction
  2. Site Management Plan (SMP)
  3. Case Closure Summary

The case closure will restrict the use of the Property to the current commercial uses as summarized in the Deed Restriction. If the use of the Property is changed,
additional investigation and/or remediation would likely be required. If subsurface work will impact the subsurface in the area of contamination, precautions are necessary to protect workers as detailed in the SMP.

ERAS has closed or is in the process of obtaining low threat solvent case closure for sites on Wright Avenue in Richmond (RWQCB), Hegenberger Road in Oakland (Alameda County Health Department) and Landess Avenue in Milpitas (Santa Clara County Health Department).

Please contact ERAS if we can assist you with any aspect of case closure or to serve your Phase 2 investigation needs.