latest update.

for whoever is interested...



Friday, May 06, 2005 3:45 PM 55296 I-99_PennDOT_Weekly_Update-05-06-05


On-Going Tasks

„h A new sedimentation Basin (known as 1A) has been constructed. It is geographically located before Basin 1. Sedimentation Basin 1A will be used to treat runoff from the Cut face, Pond L and Skytop. Excavation for Basin 1A is complete. Emergency spillway has been constructed. The liner, inlet and energy dissipater have been installed. The basket, outlet and silt fence around the stock pile have been installed. The pH meter and treater have been wired with electricity. The correct pH sensors have been completely installed and are now hooked up to the emergency phone system. The system is set up to call five emergency contacts if the pH level becomes less than 6 or greater than 9. There are three sensors set up around Basin 1 and 1A. The basin is currently being used as a treatment basin.
„h Drainage enhancements to the Siebert Basin continue. Contractor has completed the inlets that drain the clean water from the linear into Siebert Basin. Skelly & Loy has revised the storm water proposal to direct the clean water runoff from the Siebert linear to a new clean water basin.
„h PennDOT has directed the drilling contractor for the Bauxsol to install three more monitoring wells in the fill near structure 317. This will be done the week of May 9th.
„h Installation of the geo liner and PVC liner on the cut slope at Section C12 is now on hold due to the plan to pilot test Bauxsol.

Final Remediation

„h Currently, there are three options for final remediation.
The first is the Engineered Rock Placement area. PennDOT is awaiting a final
evaluation report for the potential location of the Engineered Rock Placement area.

The second is a fly ash disposal and mixing procedure at an off-site location. Some
meetings have been held with DEP regarding the fly-ash alternative. A field review of
the site has been conducted. DEP has returned comment regarding the site. Those
comments have been forwarded to the company for their review and consideration.

The third alternative is the use of Bauxsol. PennDOT has submitted a written
Draft proposal to DEP outlining plans to perform a large scale pilot test to treat the
Buttress/Bifurcation area with Bauxsol. Substantive results on the Bauxsol testing are
expected by mid-summer. PennDOT plans to test the Bauxsol on the
Buttress/Bifurcation area, the small cut face at the top of Skytop and at Structure 317
„h fill area. PennDOT has submitted a proposal to DEP to treat the Buttress/Bifurcation area with Bauxsol. The proposal includes injecting the Bauxsol and covering with a Bauxsol slurry. The drilling sub-contractor has begun to test drill the slope to determine the drilling procedure and equipment needed to install the Bauxsol. Bauxsol material will not be available until the end of May. Structure 317 Fill: PennDOT proposes to test Bauxsol at the 317 fill site. Application will include injection, slurry, and drip..and a permanent, reactive barrier.
Identification of the proper choice (or choices) for final remediation will be made as
soon as possible.

„h PennDOT and DEP will issue an updated Newsletter by the end of May that details the three alternatives.
„h RA 24 Basin: PennDOT has porposed to apply Bauxsol to this basin. A spray application will be used in an attempt to alleviate the upwelling of ARD prior to reaching Sedimentation Basin M.
„h PennDOT is considering a plan for the Cut Faces for final remediation. The cut faces could be covered with impervious material in order to protect them from precipitation. Acid generation appears to be created on these areas by precipitation. It may be possible to cover the cut face slopes with Bauxol to neutralize the ARD runoff. The cut faces would then be covered with the PVC liner and geo web to create a ground cover for vegetation. The contractor has been directed to hold any additional work in order to complete the PVC liner on the cut slope. The Department has now submitted a proposal to the DEP outlining plans to inject and treat this area with a Bauxsol slurry.