ERRS and START contractors and EPA OSC mobilized to the site on Monday April 20, 2015.  START drove the EPA Region 10 communications rig to be used as the site's command post.  Equipment was also delivered on Monday to the site and set to promptly start the planned repairs (described below) on the repository on Tuesday morning.   

·        Repair the settled areas of the asphalt to allow for proper surface water drainage and to prevent surface water from ponding on the asphalt near the engineered retaining wall;

·        Establish vegetation in the dry retention basin by adding additional top soil and adding a new seed mix optimized for local climate conditions;

·        Reconstruct the surface details of the corrugated metal pipe around the dry well to allow for better drainage of surface water in the dry retention basin;

·        Add a gravel apron at the eastern edge of the dry retention basin to allow for better drainage of surface water from the asphalt parking area;

·        Construct ramps at the northeastern and southwestern edges of the retaining wall to allow for better access to the lower sections of the wall for inspections and maintenance.

See POLREP #6 for activities conducted April 20 through April 23, 2015.  See POLREP #7 for activities conducted April 24, 2015 through April 28, 2015. This POLREP covers the operational period from April 29, 2015 through May 4, 2015. 

Wednesday, April 29

1.      ERRS surveyed the asphalt repair area and performed final grading of subbase to receive asphalt cap.

2.      ERRS completed the dry retention basin. The basin was graded, watered, seeded, and mulched. NRCS conducted a site visit to observe seeding and mulch, and discuss site needs for successful revegetation on basin.

3.      START performed dust monitoring with the DataRAMs, and the results were all less than the site action limit. No air sampling was conducted.

4.      ERRS completed the lower access ramp. The ramp was graded, surfaced with ¾”-minus aggregate and compacted. Side slopes of the ramp were seeded.

5.      Southwest access ramp was seeded.

6.      START marked locations along upper and lower levels of retaining wall placement of permanent survey markers, to be conducted by survey contractor.

7.      All work was completed except for the paving of the asphalt repair area, and installation of the parking space stoppers.

8.      ERRS decontaminated rental equipment, removed site solid waste, performed final parking lot sweeping and cleaning, and demobilized from the site. START and one ERRS to remain for final paving to be conducted on May 1, 2015.

Thursday, April 30

No work was conducted at the site.

Friday, May 1

1.      START and ERRS on site to observe paving of asphalt repair area.

2.      ERRS subcontractor arrived on site to perform in-situ compaction testing of the asphalt in the asphalt repair area. Initial tests indicated low compaction (88-91%), and the asphalt was compacted and tested again. All results met or exceeded the 92% compaction standard, and ranged from 92% to 94.8%.

3.      Pavement contractors noted a low area in the existing western asphalt patch. They placed a small float of asphalt, approximately 2 feet by 4 feet, to fill in some of the low area extending from the western edge of the new asphalt repair area.

Monday, May 4
1. Subcontractor installed sealer on asphalt joints.
2. Parking bumpers were installed on the asphalt parking area along the top of the retaining wall.  
3. Concrete blocks were placed along the slope above the access ramp to the lower part of the wall on the  east side of the pavement.
4. ERRS checked the drainage of new asphalt surface by spraying it with a garden hose.
5. ERRS completed demobilization of crew and equipment, including removing tools and trash.


2.1.3 Enforcement Activities, Identity of Potentially Responsible Parties (PRPs)