refer to previous documents
During the late morning and thru the afternoon of 03/17/05 EPA, START and REAC personnel scanned approximately 1600 student lockers. These included both hall lockers and gym type lockers. EPA followed a strict SOP which minimized EPA and contractor personnel coming into contact with the lockers. Only one locker exhibited vapors. This locker was further examined by DCDOH and DCPS.
On 03/17/05 EPA OSC again reminded DCPS officials that further investigation of all lab sinks and traps for Hg should occur. The OSC, based on screening data from START and REAC personnel, determined the potential for historic spills of Hg in the labs and residual Hg remained from improper or incomplete cleanups. DCPS officials indicated they would hire a contractor to further investigate.
On 03/18/05, the Site Clearance and Review Committee submitted its findings to the Division Director. The following was provided:
"The Cardozo High School Mercury Incident Review Committee (Committee) was established in March 2005 at the request of the Environmental Protection Agency (EPA) Administrator. The Committee was established to review the mercury response conducted by EPA at the Cardozo High School in the District of Columbia. The Committee was to review the removal methods and environmental characterization and assessment activities conducted by EPA in order to evaluate the effectiveness of the cleanup effort. The Committee was tasked to make specific recommendations on whether Cardozo High School may be re-occupied and, if not, what additional measures were necessary. The Committee was established as an objective advisory group, not a decision-making body.
On March 16, 2005 the Committee convened at Cardozo High School. EPA response staff provided a detailed briefing to the Committee and answered multiple questions posed by committee members. A prolonged guided tour of the facility followed to familiarize the committee members with the spill scenes, overall school layout and removal/characterization methods. The Committee reconvened to review data and documentation (including sampling and monitoring data), asked additional questions of the EPA response staff and deliberated privately to reach a conclusion on a re-occupancy recommendation.
Based on our review, the Committee believes that the mercury spills which prompted EPA’s response have been successfully remediated and the identified spills no longer present a reason for precluding re-occupation of Cardozo High School. This conclusion is subject to any limitations still pending by the District of Columbia and completion of cleanup or related activities under the direction of other parties.
The Review Committee supports our conclusion based on:
• the use of proper personnel decontamination measures and proven and accepted mercury decontamination means and methods,
• the use of repetitive air monitoring and detailed visual investigation procedures conducted by EPA within the facility during and after decontamination measures were completed. Several of these procedures went beyond routine mercury cleanup practices in an effort to more fully address the several releases that were identified over the course of the response,
• all sixty–eight confirmatory air samples collected and designed to detect any residual mercury vapors resulted in laboratory reported mercury air concentrations below 1.0 microgram/cubic meter (ug/m3). This concentration is widely viewed by the public health community as acceptable for residential occupancy (a more frequent and longer exposure duration than that occurring through normal school attendance) and is based on the Agency for Toxic Substance and Disease Registry’s chronic Minimal Risk Level (0.2 ug/m3) and EPA’s similarly derived mercury Reference Concentration (0.3 ug/m3).
It is important to note that this review only considered the EPA mercury response effort within the Cardozo High School. The Committee did not address any response activities conducted by the District of Columbia (e.g. cleanup of school laboratory chemicals, residential mercury screening, etc.).
The Committee understands that air monitoring of the interior of approximately 1600 individual lockers was completed early this morning. The onsite EPA On Scene Coordinator reported to the Committee chairman that only one locker was found to contain slightly elevated mercury vapor readings (~ 3.0 ug/m3). Locker contents were removed, bagged and, based on mercury vapor readings of the bagged contents, properly disposed. After the contents were removed, mercury vapor readings collected from inside the locker have consistently read below 1.0 ug/m3. The Committee sees no reason to revise its recommendation based on this discovery.
All Committee Members have reviewed and concur with this statement. A listing of Committee members is attached."
On 03/18/05 in the late afternoon hours, the DCPS contractor, hired to investigate the lab sinks and traps, reported that Hg beads were detected on the floor in front of a sink trap in lab 212. The contractor was to merc vac, decontaminate and continue its investigation. DCDOH and DCPS were notified. Oversite of this cleanup is to be handled by DCDOH. No further action or oversite is required by the OSC.
It is anticipated that the school will reopen early the week of 3/21/05. DCDOH was provided all EPA data. Reoccupancy certification will be provided by the DCDOH.
Followup media and community relations activities will occur prior to reopening of the school.
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