Thinning Out Colorado’s Air

October 2004

The scarcity of oxygen in high-altitude Colorado is something to which many out-of-state visitors can attest. Now, based on a recent decision by the executive director of the Colorado Department of Public Health and Environment (CDPHE) something else will be scarce in Colorado air: trichloroethylene (TCE). Colorado’s new policy addresses screening and remediation levels of TCE that may be present in indoor air and puts our state at the forefront of this issue.

Airborne TCE first became an issue in Colorado during cleanup of contaminated groundwater emanating from the Redfield Scope facilities in Southeast Denver. TCE is a man-made, pale blue, non-flammable, odorless chemical that primarily is used as a solvent cleaner in the metal and automotive industries. While individuals can be exposed to TCE through touching, eating, or drinking the substance, exposure most commonly occurs through inhalation. Airborne TCE may be found indoors from everyday household products such as adhesives, paint removers, carpet cleaners and paint removers. In general, these household items result in TCE background levels in homes in the Denver metropolitan area ranging from 0.2-0.5 micrograms per cubic meter of air.

When the executive director announced the proposed policy, he stated that Colorado needed to move forward with a TCE risk management policy because there is no definitive policy set at the national level. In fact, CDPHE’s Hazardous Materials and Waste Management Division has conducted some of the most extensive work on TCE in the nation. Currently, the Environmental Protection Agency continues to review the results of the new scientific studies on the effects of TCE and has therefore not yet adopted a permanent toxicity value for TCE. According to CDPHE, Colorado’s new standards reflect the department’s interest in establishing TCE limits that are protective of public health and which provide measurable guidance for remediation.

The newly increased standards in Colorado requires screening (the first test of whether cleanup should be required) for TCE at a level of 0.016 micrograms per cubic meter of air. If the TCE levels fall between 0.8 to 1.6 micrograms per cubic meter of air, CDPHE will then investigate further to decide whether remedial action is necessary. Under the terms of the new policy, cleanup is required at or beyond a level of 1.6 micrograms of TCE per cubic meter of air.

This legal update is for informational purposes only as a service to clients and other friends, is not a complete summary of the rules relating to the subject matter discussed above, and is neither to be construed as legal advice nor intended as basis for decisions in specific situations. For more information about this subject matter or other recent developments, please contact the attorneys in our Environmental, Energy and Resources practice group or any other attorney in our firm with whom you normally consult by calling (303) 825-4200.