The EPA removal action which was initiated in August 2005 and halted in January 2006 was re-started on June 1, 2006. The scope of work for Phase 2 activities involves construction of a cap and a sheet pile wall to isolate an area of high VOC contamination in soil (total VOCs in soil > 10,000 ppm), and to cutoff the offsite migration of contaminants discharging into a nearby storm drain. (See Previous POLREPs and the Action Memos approved for this Site for a more complete description of site background).
An Action Memo clarifying the Scope of Work required to complete the removal action was signed on June 5. The ERRS Task Order was modified on June 14 by adding $450,000 in removal funding.
The estimated time to complete work is by the end of August 2006.
The EPA OSC was onsite on 07/05-06, 07/17, and on 07/25-27. The U.S. Department of Interior, Bureau of Reclamation (BOR) has provided a federal government representative to be at the site daily in the OSC's absence. The following summarizes the highlights and other important findings observed during the reporting period:
A sheet pile wall measuring 130' long by 63' wide was completed on 07/15. Pile sections which encircle a floor slab covering the most highly contaminated soils onsite were driven to a minimum depth of 6' BLS, and were driven in some instances as deep as 20' BLS in order to be seated firmly in the underlying clay layer. ERRS personnel and equipment configuration was modified once pile driving operations were finished on 07/15. ERRS resources currently onsite are as follows:
• 1 Project Manager (PM)
• 1 Field Clerk
• 3 Equipment Operators
• 1 CAT 320CL track excavator w/bucket.
• 1 Linkbelt 80 small track excavator w/vibrating compaction attachment.
• 1 CAT 924 rubber tire loader w/bucket.
• 1 Ingersoll Rand SD-70D self-propelled vibratory sheepsfoot compactor.
• 1 Case 650K dozer (arrived onsite at 1600 hrs).
• 4 pickup trucks.
-On 07/17, while working on the construction of a perimeter drain around the sheet pile wall, ERRS crews encountered an unexpected source of highly contaminated soils, characterized by visible discoloration and a strong solvent odor. Further investigation revealed that additional (and possibly significant) volumes of contaminated soils exist in other areas of the Site, which were not predicted based on a review of past investigative work. This discovery prompted initiation of:
(1) discusssions with engineers for the City of Ludlow to explore raising the final grade elevations for proposed reuse plans to allow for a greater volume of material to be placed under the cap.
(2) profiling of soils for possible offsite disposal, if necessary, and
(3) expansion of the perimeter drainage system to other areas upgradient of the newly discovered subsurface contamination, in an attempt to re-route subsurface drainage away from suspected hot spots.
The perimeter drain for the north end of the Site was completed on 07/25. By visual observation, subsurface water exiting the perimeter drain now appears to be free of leachate, and efforts are underway to further analyze this material for confirmation.
- With one notable exception, work activities continue in Level D PPE. On 07/20, First , the MultiRae Plus PID recorded organic vapors in the cab of the Linkbelt 80 excavator in a range of 5-12 organic vapor units (o.v.u.). This required an upgrade to Level C PPE, until 1300 hrs., when readings dropped below the action level of 5 o.v.u.
On 07/27, OSC Smith met with KYDEP Superfund Branch personnel, and the City of Ludlow to update the status of the Site. Notably, the OSC requested that the City provide more detailed info. on the elevations to which the cap can be built such that it doesn't interfere with future construction operations. Furthermore, EPA and KYDEP agreed on the location for installing a shallow and a deep monitoring well at the site perimeter in order to evaluate for potential contaminant migration offsite.
- complete construction of cap.
- construct drainage system in areas upgradient of where additional soil contamination has been discovered.
- demolish remaining concrete structures which interfere with site reuse plans, and remove contaminated soils discovered during demolition.
- re-grade the Site to allow for positive drainage.
- re-seed the newly graded areas to prevent soil erosion.
Above average rainfall for the area has slowed the removal action. Current output is about 80% of maximum due to lost hours and days for weather-related reasons. In addition, contaminated soils being placed under the cap are becoming too wet at times to allow for adequate compaction.
As a result, it is anticipated that the completion of the removal action may take longer than originally anticipated. Consequently, the OSC will prepare an Action Memorandum requesting an extension to the 12 month statutory limitation on removal actions. While no additional funding needs are expected at this time, the OSC will re-allocate funds from the contingency provided under the existing approved budget to cover any unknown expenses.
|
