The Powhatan Mining Company site is the location of a former asbestos processing facility. The mill operated from approximately 1920 to 1980 primarily processing anthophyllite asbestos. Asbestos ore for the mill was mined in Maryland until about the 1940s and later brought in from several States including California, Georgia and Alabama. The site is bordered on all sides by residential properties and the residential yards to the southwest lie within feet of the former processing facility and in the path of site runoff. In 2006, the property to the east of the former mill was subdivided into residential lots for new home construction. From 2006 to 2008, the residential lots were cleared and graded and retention ponds were installed. Development ceased after only two homes were constructed.
The former processing facility is a multi-story building with a loading area on the northeast end (cement block portion) and a processing area at the southwest end (rusted metal portion). The asbestos fiber extraction process took place inside the building complex. Asbestos ore was reportedly received and first dried in the cement block portion of the complex. Further processing of the rock ore is believed to have occurred in the metal portion of the facility, a multi-level, timber-framed structure with stone foundation and corrugated metal siding. In the milling operation believed used at this facility, the asbestos ore was first crushed to a normal, even size and then dried. Fiber extraction then occured through a series of crushing operations, each followed by vacuum aspiration of the ore running on a vibrating screen. On the screen, the fibers were released from the ore and collected into a vacuum system. Fibers recovered from consecutive vibrating screens were brought to cyclone separators, and the air filtered to remove the finer, suspended fibers.
The property was brought to EPA's attention by the Maryland Dept of the Environment. After an initial assessment, a non-emergency Removal Action primarily intended to secure building openings was initiated by the OSC in a Special Bulletin dated August 11, 2009. More recent sampling data and conditions warranted a time-critical action. A time-critical Action Memorandum for the site, concurred on by HQ, was signed on June 8, 2010. In addition, a memorandum authorizing demolition and compensation to the property owner was approved by the Region and HQ on this date.
The U.S. EPA will be conducting removal activities at the site in order to deconstruct the facility and remove/cover soil which may pose a threat to public health and/or the environment. During activities which will cause significant disturbance of interior dust or outdoor soils, samples will be collected from personal sampling devices on cleanup personnel to determine if proper levels of protection are being used at the site. Additional air samples will be collected along the perimeter of the site to confirm that engineering controls are protective of the surrounding community.
Construction of the three-stage decontamination room within the northeastern access door of the main structure is completed. This access door will be the primary entrance and exit point for all personnel during removal activities to the structure. The floor and stairs in the southside of the structure continue to be secured. Critical barriers (windows and openings) have been be isolated in the regulated area by sealing with a double layer of 6 mil of plastic.
Since the decon unit and engineering controls have been established, the owner's personal items not specified as waste are beginning to be be cleaned. Conex boxes have been procured and are now used to house the owner's personal belongings after cleaning.
Perimeter and personnel monitoring indicate that engineering controls and the selected personal protective equipment are satisfactory.
On 8/31, EPA received a letter from the State Historic Preservation Officer indicating that deconstruction of the former Powhatan Mining facility can proceed.
EPA finished distributing notification letters to immediately adjacent residents. The notification letter highlighted the procedures of activity based air sampling (ABS).
Following a letter and email sent by the OSC to the County, the OSC and ERRS RM met with the Baltimore County Zoning Office on 9/3 to dicuss requirements for the construction of the owner's new garage. The Zoning Office indicated that application for a variance regarding size and height of the proposed structure will be necessary. Appropriate forms and instructions were provided to the OSC and the hearing process was described.
A Sampling Plan was developed for ABS and soil sampling at three adjacent properties. A laboratory was acquired for offsite analysis of the samples. ABS and associated soil sampling was conducted on 09/02-03/2010.
- Continue with cleaning owner's personal items and move outside to storage containers.
- Continue bagging asbestos-containing waste for later transport and disposal.
- Continue coordination efforts with owner, Baltinore County Zoning and other parties.
- Conduct perimeter and personnel sampling periodically as determined necessary.
EPA will work with the property owner to submit all necessary forms and maps for the variance application..
The ERRS crew will continue decontaminating the owner's personal belongings by vacuuming and wet wiping. Items identified as waste will be properly bagged for disposal as asbestos-containing waste.
Additional soil sampling is planned.
Submission of zoning hearing forms and maps and ultimate outcome.
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