Site Description
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.
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, air samples periodically 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.
Current Activities continiuing for period:
- ERRS continues cleaning the owner's personal items for conex box storage and bagging items to be discarded as asbestos-containing waste.
11/29/10 – START obtained equipment for Microvac and personnel air sampling. OSC Kelly not on site due to office responsibilities.
11/30/10 – START conducted pre and post decon microvac sampling on exposed car equipment inside the cement block building.
- OSC directed START to have the Weston cost estimator develop an estimate on replacing the back wall and roof of the concrete block building should a decision be made to demolish only the back sheet metal portion of the former facility and leave the concrete block portion in place (assumption is that the back wall and roof of the concrete building would need to be replaced based on how the two portions of the facility are currently constructed).
- the OSC worked on a draft "options paper" to forward to management per the OSC's discussions with the owner.
- obtained construction drawings from the Valerie Manor/Portrait Homes developer for use in preparing E&S control drawings for implementation after demolition and new building construction are complete.
- Rasche Bros provided a new cost estimate based on items requested in the owner's 11/18 letter to the OSC.
12/01/10 – The property owner stopped by the mailed copy of the Baltimore County Asst Zoning Commissioner's decision order. The Zoning Commission approves the variance request and new building construction plans can proceed. The order has several add-on requirements directed to the owner.
- START conducted personnel and stationary air sampling. Utilized two Gillian pumps for 8 hours, one SKC pump for 8 hours and one SKC pump for 30 min.
- Photos taken of specific sections of the concrete block building interior and roof for use by the cost estimator.
- the OSC completed the draft option paper and forwarded to management.
12/02/10 – The OSC and ERRS RM held a meeting with the property owner. Difficult discussion at times but progress made. The owner seems agreeable to a post frame building provided upgrades are included. The OSC agreed in principle but said he must discuss with EPA management.
At the OSC's urging, the owner agreed to meet with a Rasche Bros rep onsite to have all his construction-oriented questions and concerns answered since the OSC and RM cannot answer very specific items.
- the Weston cost estimator provided a cost estimate for a new roof and back wall on the existing concrete block building.
12/03/10 - Received the microvac and air sampling results from the sampling on 11/30. Personnel and interior stationary results were approximately an order of magnitude below the OSHA PEL of 0.1 f/cc(range was 0.012 to 0.037 f/cc). Microvac results were acceptable for return of items to the owner.
- the OSC conferred with the EPA CO for the ERRS contract on the potential need to re-bid the garage construction based on the upgrades requested by the owner. The CO indicated that a bid amendment would be sufficient, no need to re-bid. The OSC directed the RM to do so.
- RM and the OSC discussed future plans for cleaning Bay 1, the Bay most used by the owner for auto repair work.
- the OSC emailed a status report to to management and ORC.
12/06/10 - OSC not at the site due to work in Phila area on another project.
12/07/10 - The owner, OSC, RM and Rasche Bros reps held a meeting onsite to discuss the proposed building and answer the owner's concerns. The Rasche foreman explained load calculations, discussed the location and size of two attic access hatches, identified that R-19 insulation will be in the walls and R-30 in the attic space, and indicated that soffit or wall vents will be placed at the roof. The contractor will provide a single catwalk that runs the length of the attic space. The foreman answered additional questions from the owner on warranties and construction specifics. All parties appeared satisified with the results of the meeting.
- The Weston E&S engineer and local surveyor were on site to evaluate the current property conditions for drainage purposes. The Weston engineer will be working on developing a complete drainage layout for the property to accommodate the additional runoff that will be created by the new building as well as from the open space created by the demolition of the existing structure. Assuming agreement by local authorities, runoff will be tied into existing storm water lines. The Weston engineer will also provide required compaction rates and fill type for the new garage footprint.
and the garage entrance on the side nearest the owner's home (this area has a considerable slope).
12/08/10 - The OSC drafted a document for management justifying construction of a post-frame building with upgrades.
- The OSC received revised cost estimate/design from Rasche Bros for upgrades for the garage building. The OSC forwarded the new design to the owner for review.
12/09/10 - The OSC received comments from the owner on the new design.
Owner satisfied except he noticed that the design missed several electical items currently existing in his building (e.g. current design calls for 5 flourescent lights, current concrete block building has ~30; current design only shows 2 switches, building has 4). ERRS foreman walked through the building to document what currently exists. The OSC agreed to get new costs for these items and will re-confer with management then owner.
- the OSC's manager contacted the OSC to say management concurred with the OSC's decision to proceed with planning for constructing a new building with upgrades (provided new electric costs aren't excessive).
12/10/12 - The OSC and RM continued to confer on cleanup activities. Next task is to clean above the plastic "ceiling" in Bay 2. The plastic is located several feet below the roof and has collected a significant amount of asbestos-containing dust and particles over the years. The crew will develop a plan to vacuum the dust and remove the plastic in a manner that will cause as little disturbance as possible.
- the OSC reviewed project costs to date.
12/11/10 - OSC at site until 1 pm. Completed administrative tasks and emailed the owner on plans to dispose of white goods at the Carroll County Landfill.
Planned Removal Actions:
- Work out details on addressing owner's items in Bay 1 and cleaning area above plastic in Bay 2.
- Transport and dispose additional ACM waste in a week or so.
Next Steps:
- Continue to coordinate with the site owner on the fate of interior items and the likely progression of upcoming work.
- Continue efforts to subcontract out the new garage construction (based on the cost proposal values, the CO's concurrence will be necessary.)
- Meet with demo bidders next week.
Key Issues:
Work out garage construction details and the progression of future removal activities with the owner.
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