Under various federal, state and local laws and regulations relating to the environment, as a current or former owner or operator of real property, we may be liable for costs and damages resulting from the presence or discharge of hazardous or toxic substances, waste or petroleum products at, on, in, under or migrating to or from such property, including costs to investigate, clean up such contamination and liability for harm to natural resources. Such laws often impose liability without regard to whether the owner or operator knew of, or was responsible for, the presence of such contamination, and the liability may be joint and several. These liabilities could be substantial and the cost of any required remediation, removal, fines or other costs could exceed the value of the property and in some cases our aggregate net asset value. In addition, the presence of contamination or the failure to remediate contamination at our properties may expose us to third-party liability for costs of remediation and/or personal, property, or natural resources damage or materially adversely affect our ability to sell, lease or develop our properties or to borrow using the properties as collateral. In addition, environmental laws may create liens on contaminated sites in favor of the government for damages and costs it incurs to address such contamination. Moreover, if contamination is discovered on our properties, environmental laws may impose restrictions on the manner in which property may be used or businesses may be operated, and these restrictions may require substantial expenditures.
We obtain Phase I, or Phase II as appropriate and permitted by the seller, or similar environmental site assessments conducted by independent environmental consultants on most of our properties at the time of their acquisition or in connection with subsequent financings, however, these assessments are limited in scope and are not updated in the ordinary course of business absent a specific need and therefore, may not reveal all environmental conditions affecting a property. This may expose us to liability related to unknown or unanticipated environmental matters. Unless required by applicable laws or regulations, we may not further investigate, remedy or ameliorate the liabilities disclosed in the existing Phase I's or similar environmental site assessments, and this failure may expose us to liability in the future. While we maintain portfolio environmental and some site-specific insurance policies, they may be insufficient to cover any such environmental costs and liabilities.
Some of our properties have been or may be impacted by contamination arising from current or prior known or unknown uses of the property, or adjacent properties, for commercial or industrial purposes. Such contamination may arise from spills of petroleum or hazardous substances or releases from tanks used to store such material known or suspected to exist at a number of our properties which may result in further investigation, remediation, or deed restrictions. Further, certain of our properties are adjacent to or near other properties that have contained or currently contain petroleum or other hazardous substances, or at which others have engaged or may engage in activities that may release such hazardous substances. Adjacent property uses are identified in standard ASTM procedures in Phase I environmental studies, and if warranted based on adjacent property concerns a Phase II environmental study may be obtained. In addition to a blanket environmental insurance policy, as needed, we may obtain a standalone environmental insurance policy for certain properties with commercially reasonable terms that provide coverage for potential environmental liabilities, subject to the policy's coverage conditions and limitations. However, these policies are subject to certain limits, deductibles and exclusions, and insurance may not fully compensate us for any environmental liability. From time to time, we may acquire properties with known adverse environmental conditions where we believe that the environmental liabilities associated with these conditions are quantifiable and that the acquisition will yield a superior risk-adjusted return. We usually perform a Phase I environmental site assessment at any property we are considering acquiring. Phase I environmental site assessments are limited in scope and do not involve sampling of soil, soil vapor, or groundwater, and these assessments may not include or identify all potential environmental liabilities or risks associated with the property. Even where subsurface investigation is performed, it can be very difficult to ascertain the full extent of environmental contamination or the costs that are likely to flow from such contamination. We cannot assure you that the Phase I environmental site assessment or other environmental studies identified all potential environmental liabilities, or that we will not face significant remediation costs or other environmental contamination that makes it difficult to sell any affected properties. Also, we have not always implemented actions recommended by these assessments, and recommended investigation and remediation of known or suspected contamination has not always been performed. Contamination may exist at many of our properties, and governmental regulators or third parties could seek to force us to contribute to investigation or remediation of known or suspected contamination. As a result, we could potentially incur material liability for these issues.
Environmental laws also govern the presence, maintenance and removal of asbestos-containing building materials, or ACBM, and may impose fines and penalties for failure to comply with these requirements. Such laws require that owners or operators of buildings containing ACBM (and employers in such buildings) properly manage and maintain the asbestos, adequately notify or train those who may come into contact with asbestos, and undertake special precautions, including removal or other abatement, if asbestos would be disturbed during renovation or demolition of a building. In addition, the presence of ACBM in our properties may expose us to third-party liability (e.g., liability for personal injury associated with exposure to asbestos).
In addition, the properties in our portfolio also are subject to various federal, state and local environmental, health and safety requirements, such as state and local fire requirements. Moreover, some of our tenants routinely handle and use hazardous or regulated substances and wastes as part of their operations at our properties, which are subject to regulation. Such environmental, health and safety laws and regulations could subject us or our tenants to liability resulting from these activities. Environmental liabilities could affect a tenant's ability to make rental payments to us. In addition, changes in laws could increase the potential liability for noncompliance, including evolving regulatory evaluation and scrutiny of per- and polyfluoroalkyl substance known as PFAS. This may result in significant unanticipated expenditures or may otherwise materially and adversely affect our operations, or those of our tenants, which could in turn have an adverse effect on us. Further, these environmental, health and safety laws could become more stringent in the future, and this could subject us or our tenants to new or greater liability.
We cannot assure you that remedial measures and other costs or liabilities incurred as a result of environmental issues will be immaterial to our overall financial position. If we do incur material environmental liabilities in the future, we may face significant remediation costs, and we may find it difficult to sell any affected properties.