Alewife Study Group > government > September 19 2001, Cambridge Public Health Department Search 

Final decision about trench, from Cambridge Public Health Department
to W. R. Grace


September 19, 2001

Mr Robert F. Jenkins, Vice President Engineering & Manufacturing Support
W.R. Grace & Company - CONNECTICUT
62 Whittemore Avenue
Cambridge, MA 02140

FINAL DECISION REGARDING UTILITY TRENCH EXCAVATION

Dear Mr Jenkins,

The Cambridge Public Health Department has reviewed all public comments and all responses provided by W.R. Grace as of September 17, 2001. The conditions under which excavation of the previously described Utility Trench may be conducted will conform to the provisions stated in the Draft Decision Regarding Utility Trench Excavation (August 2, 2001) reproduced at the end of this document with the following additional condition to be required: The placement of two airborne monitoring locations at predetermined "upwind" and "downwind" locations must be configured to allow perimeter coverage regardless of wind direction. In order to assure full coverage of this "L-shaped" trench it will be necessary to allow one of the two perimeter monitoring locations to be movable during work on the "hooked" portion of the trench. This will allow at least one device to be "downwind" at all times regardless of the wind direction and in the event of a breach in the tented structures. Once work on this lateral portion of the trench has been completed then fixed monitoring may be used for the remainder of the project.

Comments received by this department raised several issues, some procedural and others logistic or technical. The issue of primary concern to this department is the selection of appropriate trigger levels to cause suspension of operations and employment of additional mitigation measures. The selection of a very low, but positive, trigger level for real-time fiber monitoring (0.02 PCM-determined fibers/cc) was appropriately derived on the basis of state Department of Environmental Protection (DEP) guidance. In consideration of the requirement to impose "negative air" tenting over this trench and the inability of the real-time devices to distinguish between asbestos and other fibers, this trigger level is inherently conservative. Furthermore, the EPA comments that indicate that a trigger-level should be set "using the detection limit of the available analytic standard" would not guarantee a detection limit as low as 0.02 fibers/cc. In its final approval the DEP has indicated that this trigger level is fully protective.

Comments specifically questioning full procedural compliance with the Massachusetts Contingency Plan (MCP) and the state Public Involvement Process (PIP) are not the jurisdiction of this department.


Sam Lipson
Director of Environmental Health
Cambridge Public Health Department
City of Cambridge 617-665-3838



August 2, 2001

Mr Robert F. Jenkins, Vice President Engineering & Manufacturing Support
W.R. Grace & Company - CONNECTICUT
62 Whittemore Avenue
Cambridge, MA 02140

Re: DRAFT DECISION REGARDING UTILITY TRENCH EXCAVATION

Dear Mr Jenkins,

The Cambridge Public Health Department is issuing this draft decision in order to establish the dust and airborne asbestos mitigation measures required under the Asbestos Protection ordinance by the responsible party, W.R. Grace, during utility trench excavation on its property at 62 Whittemore Avenue in Cambridge. This department also acknowledges receipt of explanatory documentation sent by representatives of W.R. Grace on Friday, July 27, 2001 regarding the nature of the Utility Trench work proposed. This excavation work was previously described in the Final Utility Trench Excavation Release Abatement Measure (RAM) Plan/Asbestos Soil Management Plan (ASMP) submitted in May 2001, but further details were solicited in order to determine whether the "underground utility maintenance" exemption in the Asbestos Protection ordinance should apply.

A review of the history and placement of the power, telecommunications, air, gas, sprinkler, and steam utilities described by the responsible party suggests that the extant underground utility corridor has been in place for several decades. It is also apparent that outdated electrical power lines do need to be replaced and that best engineering practices and basic safety considerations impose limitations on the placement of these lines above ground. Though above-ground placement of these 13,000-volt power lines can be carried out safely, some potential hazards would nevertheless be introduced by this configuration (e.g. risk of lightening strikes) and significant soil disturbance would be required in the construction of a pole line along this corridor for necessary support. Above-ground construction does not appear to be the best option for such high-powered lines and, furthermore, concerns about disruption of contaminated soil would not be eliminated if this approach were taken.

While the precise meaning of terms such as "upgrade" and "maintenance" can be debated without resolution, I believe the work described meets both definitions in some measure. Antiquated lines do represent an ongoing safety concern, but the increased capacity being introduced is clearly part of a larger modernization program intended to augment the capacity of the buildings now served by these power lines. I view the exemption language in the local ordinance as an attempt to balance immediate safety concerns associated with disturbance of soil on an asbestos-contaminated site against the potential hazard of delaying urgently needed utility repairs and maintenance. It seems apparent that this upgrade work does need to be completed within a reasonable period of time, but it also seems clear that full compliance with the Asbestos Protection ordinance would not interfere with the expeditious completion of this work or jeopardize public safety. Presumably this upgrade work could have been completed at any point in the past several years and was not carried out until now because it did not previously coincide with plans to expand the use of several older buildings. In short, the importance of this upgrade/maintenance work is quite clear and the rationale for placing these lines underground is strong, but neither the urgency implied by the emergency exemption provision nor the limited scope of work suggested by the maintenance exemption has been convincingly demonstrated.

The discretionary nature of both the emergency repair and maintenance exemptions, I believe, clearly underscores that the ordinance was primarily written to provide protection from release of airborne asbestos. Given the history of contamination on this site and the absence of emergency conditions at this time I do not believe it is appropriate to grant this work an exemption from the provisions of the Asbestos Protection ordinance under discretionary powers assigned to this department. As a consequence of being located within 500 feet of a residential property one of the conditions specified within the ordinance as a trigger for further controls has been met. Therefore this work and all other "soil disturbing activities" on this property (as defined within the ordinance) requires one of the following mitigation measures in addition to those monitoring and mitigation measures already included in the Asbestos Soil Management Plan submitted in May 2001:

Accordingly, please provide to me and to the public repository at the Main Branch of the Cambridge Public Library a revised Asbestos Soil Management Plan incorporating one or both of these additional control measures. Please contact me if you require further clarification regarding this matter. This draft decision will immediately be placed in the public repositories and will remain there for no less than 20 days after the revised Asbestos Soil Management Plan is available for public review and comment. A final decision will be issued thereafter.
Sincerely,


Sam Lipson
Director of Environmental Health
Cambridge Public Health Department
City of Cambridge       cc: Margaret Drury, City Clerk
617-665-3838



Contact the Alewife Study Group, North Cambridge Massachusetts, by email at information@alewife.org