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 continues on a three-stage decontamination room within the northeastern access door of the main structure. 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) continue to be isolated in the regulated area by sealing with a double layer of 6 mil of plastic. Once removal operations begin within the building, personal items not specified as waste will be decontaminated and saved (unless the material cannot adequately be cleaned). Perimeter and personnel monitoring have been conducted during prep activities. Based on the results from 8/24/10, engineering and personal protective equipment controls are satisfactory.
All portions of the building will be sealed as long as the portion of the structure can be reached without causing significant risk to site personnel. The decontamination area will be completed within the front access door to the structure
ERRS finished construction of the stone roadway adjacent to the former facility and along pathway areas leading to the site trailer to minimize potential migration of asbestos. .
The EPA OSC and CIC distributed a fact sheet to surrounding residential properties regarding current activities at the site.
An official from the MDE Asbestos Program stopped by briefly. He mentioned the need to get all asbestos signs up.
The OSC dropped off sampling results from the March 2010 residentail yard sampling event to homeowners. The OSC also distributed letters to homes with yards still eligible for sampling (per the OSC's judgment), urgng the homeowner to contact EPA if he/she wants to have the yard sampled.
The OSC delivered two letters to the Baltimore County Zoning Office; one prepared by the OSC and one by the property owner. The letters focus on building of the garage by EPA as compensation to the property owner following the existing building's planned demolition. The letters ask for clarification on procedures to follow, identifies the unique nature of the project, and requests an expedited process.
One of the property owner's cars was cleaned and moved outside.
Following ERRS distribution of an IFB for construction of the garage structure, only one bidder arrived on the designated site tour day. The bidder was provided with answers to questions. Another bidder sent in a cost estimate simply by viewing building photos. The OSC is discussing with the CO any additional needs.
- Continue with construction of decon chamber and sealing the building.
When complete, begin cleaning owner's personal items and move outside to storage pods.
- Continue coordination efforts with owner, Baltinore County Zoning and other parties.
- Plan for ABS sampling in selected yards.
- Conduct perimeter and personnel sampling periodically as determined necssary.
A Sampling Plan is being developed for activity based air and soil sampling at three adjacent properties. A laboratory is being acquired for offsite analysis of these samples. Sampling is expected to occur in September 2010.
EPA will distribute a notice to immediately adjacent residents that highlight the procedures of activity based sampling to occur next week.
EPA will confer with Baltimore County on zoning/permitting issues and a potential variance for construction of the new garage.
EPA will continue to coordinate with the MDE Asbestos Program.
Conex boxes will be procured to keep the owner's personal belongings in once decontaminated.
- Any need for a zoning variance to construct a new garage.
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