Testimony of

Ivan C.A. Walks, M.D.

Chief Health Officer, District of Columbia

Director, Department of Health

Hearing on the Process and Progress of

Remediating Biologically and Chemically Contaminated Buildings

United States Senate

Committee on the Environment and Public Works

December 4, 2001

Washington, D.C.

Good morning, Chairman Jeffords and Distinguished Members of the Committee on the Environment and Public Works. I am Dr. Ivan C.A. Walks, Chief Health Officer for the District of Columbia and Director of the Department of Health. With me today is Theodore J. Gordon, Chief Operating Officer of the Department of Health (DOH), and key staff members involved with the remediation of biologically and chemically contaminated buildings. We appreciate the opportunity to testify and commend you for convening this Hearing because the discussion here this morning further complements our effort to illuminate the issues regarding environmental exposures to contaminants in the District of Columbia.

This hearing also enhances our effort to continuously inform the community and involve them in decisions or procedures designed to address their concerns. As I mentioned in the Hearing on Spring Valley before the House of Representatives in July 2001, we cannot overemphasize the importance of an ongoing interaction between the District of Columbia Government and the members of the community. There can be no substitute for an informed community. That theme has been and will continue to be a guiding light for our efforts in every community in the District of Columbia, and in any other effort to prevent disease, dysfunction and premature death.

Allow me now to turn to the purpose of this hearing, i.e., the process that the District of Columbia Government is guided by in remediating biologically and chemically contaminated buildings and its progress and successes to date. My testimony will also cover the challenges that confront the District and the rest of the country, the new technologies available, and our next steps.

The DOH's Environmental Health Administration is charged with the mission of protecting human health via the prevention and control of environmentally related diseases, the prevention of environmental degradation, and the promotion and preservation of the ecological system and physical environment of the District of Columbia. When carrying out this charge, it is imperative that we follow a process that is structured, but at the same time flexible enough to allow for input from the various stakeholders. In this regard, and particularly with regard to time-critical remediations, our process is similar to that described by the U.S. Environmental Protection Agency’s “Superfund Community Involvement Handbook.”

District's Process of Remediation

The first step toward remediation that we take is to identify/define the problem. Regarding biological contamination, this step involves both the identification of contaminated regions of a building and all the possible pathways by which contamination can move beyond the contaminated zone to other locations within the building.

We then begin to explore the various remediation options. Each option is evaluated with regard to its technical effectiveness, practical feasibility, and the unintended health and ecological risks to remediation workers and the adjacent community. In other words, we perform an environmental risk assessment identifying issues and the problems or risks associated with each option.

In conducting an environmental risk assessment, several things are considered. First, we must be confident that we will achieve a successful outcome. Also with regard to each option, we also have to consider cost, exposure to the government, community hardship (emotional and physical), and length of time for the clean up. We continue to monitor and re-evaluate throughout the planning and implementation stages of the process.

From this, a prime option is then identified. We also develop a secondary or “fall back” option so that we do not have to restart from the beginning if the prime option is not selected.

Once we are almost certain that we have considered all pertinent factors, we then prepare to take a plan of action to the affected stakeholders for input and "buy in." We have learned a long time ago that there is no such thing as a successful plan, if the community has not had the opportunity to participate in it. Again, a big reason for our success in the Spring Valley community had to do with the inclusion of that community in our remediation strategy. We have had several meetings in the community briefing its residents on our findings and process for remediating. In addition, Mayor Anthony Williams assembled an independent group, the Spring Valley Scientific Advisory Panel, which includes seven specialists in the fields of epidemiology, toxicology and environmental health, as well as two representatives from the Spring Valley community.

The DOH has had significant experience in remediating biologically and chemically contaminated buildings in the District of Columbia. Within the most recent eighteen months we have experienced Legionella contamination in a correctional facility, a public school, and in a health care facility. We have had significant fungal contamination of private homes and a public high school following a flood this past summer. In one community, private homes and a District building were affected by a petroleum spill. Our successes are largely attributable to how well we communicate with the affected parties. Of course, we have a highly skilled and professional group of scientists and engineers who perform the technical risk assessment and remediation steps discussed above. However, I continue to stress the importance of communication as a key ingredient in any successful remediation plan.

Challenges Confronting the District of Columbia and the County

The particular challenge confronting the DOH in the District of Columbia and all health departments across the nation regarding biological decontamination of buildings is that the these remediations necessarily must take place in a context of emerging science. We are all traveling steep learning curves with regard to the technical and medical facts. When we use toxic chemicals to kill biological agents, the scope of that learning curve includes stakeholders both within and adjacent to the affected building.

In this regard we wish to recommend one fundamental public health principle: until we learn whether a clinically significant minimum microbial contamination level exists, we should only declare a building to have been decontaminated when all test samples achieve “no detection” levels. With regard to community exposure to toxic chemicals we should continue to maintain substantial margins of safety with regard to exposures to people in the adjacent communities.

Next steps

As we proceed to climb these learning curves, we need to share information with other state and local health agencies. Such information will include biological sampling protocols, dosing, measuring, critical bio-load levels and most of all, effectiveness data. We should expect the emergence of new chemical decontamination methods, rapid measuring technologies, and biological detection methods. Knowledge of their efficacies and protocols should be widely shared within the public health community.

Thank you for this opportunity to come before you to discuss this issue. We are happy to answer any questions you may have.