At a recent public meeting, representatives from the Environmental Protection Agency, the Maryland Department of the Environment, Honeywell International and Beatty Development Group made formal presentations focused on environmental concerns associated with the proposed development at Harbor Point in Baltimore. These organizations support the contention that there will be no significant human health and/or ecological risks associated with the Harbor Point project, situated on the site of a former chromium ore processing plant. This was also the message conveyed in replies to pointed questions from over 100 concerned citizens in attendance at this meeting.

While considerable work has been done to address problematic environmental issues associated with this project, we believe that there still remain a few important unresolved concerns that need to be addressed promptly.

We want to be clear at the outset. We are not saying that development of this site will result in meaningful human health and/or ecological risks. Rather, we are saying that additional studies are needed to reduce what can best be defined as an unacceptable level of uncertainty. More specifically, our concerns are associated with exposure of people and aquatic organisms to toxic "hexavalent chromium" — which can cause cancer if inhaled or other health problems if ingested — in the air and groundwater.

Rather than removing the hexavalent chromium when the processing plant shut down years ago, regulators entombed it on the site. Developers plan to temporarily expose it during the new construction.

In the vicinity of the Harbor Point site, between Harbor East and Fells Point, groundwater tends to flow from the north under downtown Baltimore City, then through the bottom sediments of the Inner Harbor before emerging into harbor waters. A single monitoring well in Back Bay at the Living Classrooms Foundation campus, which is immediately to the north of the Harbor Point site and outside of the capped and entombed hexavalent chromium, consistently shows that the groundwater there is nevertheless contaminated, with concentrations of hexavalent chromium at least 40,000 times larger than ambient water quality standards set for surface water supplies.

The vertical clay barrier at Harbor Point forces the groundwater to flow around the property before it enters the Inner Harbor. There is considerable uncertainty regarding the exit points for this groundwater and what happens to the hexavalent chromium carried by the groundwater.

Therefore, it is recommended that additional studies be conducted to trace the fate of the dissolved hexavalent chromium that has been detected in the Back Bay groundwater to ensure that it is not entering the Harbor water and posing a significant risk to aquatic organisms. This can be accomplished though installation of a new network of wells to track the groundwater until it enters the harbor water.

Hexavalent chromium can produce lung cancer if inhaled at certain concentrations over time. If levels in the air are found to be higher than "background" levels as a result of pilings being driven through the cap over the site during construction, action can be taken to reduce the risk to human health.

The current plan is to take samples to determine hexavalent chromium concentrations in the air on the Harbor Point site and at off-site locations juxtaposed to Harbor Point (e.g., the National Aquarium and Living Classrooms). Given the proximity of all of these sites, there is a high likelihood that hexavalent chromium levels in the air will be similar at both on-site and off-site locations.

While this sampling will provide important data, it doesn't answer the following critical question. Are background levels of hexavalent chromium in the air in the Inner Harbor higher than background levels in other areas of Baltimore?

To answer this question, off-site sampling should be expanded to include areas in Baltimore approximately 10 miles or more from the site. This additional information will allow scientists to do a comparative analysis of background levels in Inner Harbor ambient air and background levels in the air at other locations removed from the Harbor Point site.

Additional ground water studies in the Back Bay and findings from expanded air sampling should be of considerable interest to individuals residing in or near the Inner Harbor, as well as state and federal agencies involved with this issue. Most importantly, this supplementary information will help insure that sound science drives the environmental regulatory decision-making process.

Erik Rifkin is co-Director of the Mercury Project at The Center for Contaminant Transport, Fate and Remediation at Johns Hopkins University. His email is Edward Bouwer is Professor and Chair of the Department of Geography and Environmental Engineering at Johns Hopkins University. His email is

To respond to this commentary, send an email to Please include your name and contact information.